87 changed files with 589 additions and 6965 deletions
--- a/.gitignore
+++ b/.gitignore
@ -5,7 +5,6 @@ tests/*.s
 examples/*.s
 !runtime.s
 !stdlibwrap.s
 !sprites.s
 *.o
 *.exe
 *.bin
@ -26,7 +25,6 @@ graph1.pas
 graph2.pas
 chase.pas
 pcomp/libgen
 pcomp/shortgen
 pcomp/lsymgen
 pcomp/pcomp
 pcomp/sasm
@ -34,18 +32,16 @@ pcomp/sdis
 tridoraemu/tridoraemu
 **/tridoracpu.cache/
 **/tridoracpu.hw/
 **/tridoracpu.gen/
 **/tridoracpu.ip_user_files/
 **/tridoracpu.runs/
 *.log
 *.jou
 **/mig_dram_0/_tmp/*
 **/mig_dram_0/mig_dram_0/*
 **/mig_dram_0/doc/*
 **/mig_dram_0/mig_dram_0*
 **/mig_dram_0/xil_txt.*
 **/mig_dram_0/*.veo
 **/mig_dram_0/*.tcl
 **/mig_dram_0/*.xml
 **/mig_dram_0/*.v
 **/mig_dram_0/*.vhdl
 **/mig_dram_0/*.dcp
--- a/.gitmodules
+++ b/.gitmodules
@ -1,3 +0,0 @@
 [submodule "rogue"]
 	path = rogue
 	url = https://gitlab.com/slederer/ecl-rogue-m.git
--- a/LICENSE.md
+++ b/LICENSE.md
@ -4,7 +4,7 @@ All files, except where explicitly stated otherwise, are licensed according to t
 ------------------------------------------------------------------------------
-Copyright 2024-2026 Sebastian Lederer
+Copyright 2024 Sebastian Lederer
 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
--- a/README.md
+++ b/README.md
@ -1,5 +1,5 @@
-# Tridora-CPU
+# Tridora System
-The Tridora-CPU is a homebrew CPU written in Verilog and a matching software environment,
+Tridora is a homebrew CPU written in Verilog and a matching software environment,
 including a Pascal compiler and assembler.
 Everything was created from the ground up (except soldering stuff).
 Everything is as simple as possible while still being reasonably useful.
@ -8,7 +8,7 @@ Everything is open source, so you can read, understand and modify the whole syst
 ## Overview
 - homebrew CPU written in Verilog implemented on an FPGA
 - 32-bit word-oriented stack machine architecture
- running at 77 MHz on an Arty-A7 board with four clocks per instruction
+- running at 83 MHz on an Arty-A7 board with four clocks per instruction
 - has its own instruction set architecture, compatible with nothing
 - additional IO controllers on FPGA: UART (serial console), SD-Card, VGA
 - Pascal compiler written from zero
@ -30,59 +30,13 @@ has a strange mixture of features from three different eras of computing:
 - speed is like a fast 16-bit CPU, also 16-bit instruction words
 - 32-bit word size from the 32-bit era
 It might remind you of the UCSD-P-System and early Turbo-Pascal versions.
 Other inspirations were, among others, in no particular order:
 - the Novix 4016 CPU (a stack machine CPU designed for Forth, mainly by Charles Moore)
 - the J1 CPU by James Bowman (which is not entirely unlike the Novix 4016)
 - the Lilith computer by Niklaus Wirth and his team (a stack CPU designed for Modula-2)
 - the PERQ workstation (also a stack CPU designed for Pascal)
 - the Magic-1 by Bill Buzbee
 - the OPC by revaldinho
 ## October 2025 Update
 This update introduces a data cache for the Tridora-CPU. It is similar to the instruction cache
 as it caches the 16 bytes coming from the DRAM memory controller. It is a write-back cache, i.e.
 when a word inside the cached area is written, it updates the cache instead of invalidating it.
 This is important because there are many idioms in the stack machine assembly language where you
 store a local variable and then read it again (e.g. updating a loop variable).
 Since for most programs, the user stack and parts of the heap are inside the DRAM area, the data cache
 has a more noticable impact. In the benchmark program that was already used for the last update,
 the data cache results in a 50% improvement for the empty loop test. This is in comparison to the version
 without data cache but with the instruction cache, both running code out of DRAM.
 It is also noticable for compile times: With the data cache, compiling and assembling the
 "hello,world" program takes 16 seconds instead of 20. With a little tweak of the SD-Card controller
 that slightly increased the data transfer rate, the build time goes down to 15 seconds.
 Also, an audio controller was added that allows interrupt-driven sample playback via an AMP2 PMOD.
 ## April 2025 Update
 The clock has been reduced to 77 MHz from 83 MHz. Apparently the design was at the limit and
 timing problems were cropping up seemingly at random. Reducing the clock speed made some
 enhancements and bugfixes possible. Also, the project files work with Vivado 2024 now.
 Most importantly, the Tridora-CPU now has an instruction cache with a size of 16 bytes or eight instructions.
 This increases execution speed when running code out of DRAM (that is, above 64KB). In a simple
 benchmark program, the CPU is about twice as fast.
 Many programs fit into the lower 64KB of RAM, which can be accessed without latency, and will
 have no noticable speed increase.
 There have also been a number of bug fixes for the compiler and some for the assembler. This makes
 compiling even larger and more complex programs possible. An example of this is ECL-Rogue, a variant of Rogue written
 Pascal, which has been ported to Tridora-Pascal and is now included
 on the emulator image.
 ## Links/Downloads
 - the [source repository](https://gitlab.com/slederer/Tridora-CPU)
 - the [Hackaday project](https://hackaday.io/project/198324-tridora-cpu) (mostly copy-paste from this README)
 - the [YouTube channel](https://www.youtube.com/@tridoracpu/videos) with some demo videos
- the [emulator](https://git.insignificance.de/slederer/-/packages/generic/tridoraemu/0.0.5/files/12) (source and windows binary)
+- the [emulator](https://git.insignificance.de/slederer/-/packages/generic/tridoraemu/0.0.2/files/8) (source and windows binary)
- the [FPGA bitstream](https://git.insignificance.de/slederer/-/packages/generic/tdr-bitstream/0.0.4/files/16) for the Arty-A7-35T board
+- the [FPGA bitstream](https://git.insignificance.de/slederer/-/packages/generic/tdr-bitstream/0.0.1/files/3) for the Arty-A7-35T board
- an [SD-card image](https://git.insignificance.de/slederer/-/packages/generic/tdr-cardimage/0.0.4/files/13)
+- an [SD-card image](https://git.insignificance.de/slederer/-/packages/generic/tdr-cardimage/0.0.2/files/7)
 Contact the author here: tridoracpu [at] insignificance.de
@ -113,7 +67,7 @@ Two Pmods are used for a complete system:
 As the Arty-A7-35T is no longer in production, it should be easy to
 use the Arty-A7-100T instead, but this has not been tested yet.
-Other boards under consideration are the Digilent Nexys-A7 and the Arty-S7.
+Other boards under consideration are the Digilent Nexys-A7 and the Olimex GateMateA1-EVB.
 ## Pascal Language
 - Wirth Pascal
@ -122,7 +76,7 @@ Other boards under consideration are the Digilent Nexys-A7 and the Arty-S7.
 - safe strings (runtime information about max/current size)
 - tiny sets (machine word sized), that means no SET OF CHAR
 - array literals with IN-operator, which can replace most uses of SET OF CHAR
- nested procedures
+- nested procedures with some limitations
 - 32 bit software floating point with low precision (5-6 digits)
 - break and exit statements, no continue yet
 - static variable initialization for global variables
@ -153,7 +107,7 @@ Other boards under consideration are the Digilent Nexys-A7 and the Arty-S7.
 - for **rom.mem** and **rommon.prog**, find both files in the **lib** directory after running **make nativeprogs** (or **make.bat**) in the **pcomp** directory (see above)
 ## Building the FPGA bitstream
- install Vivado (April-2025-Update tested with 2024.2)
+- install Vivado (known to work with 2020.1, known NOT to work with 2024.1)
 - install the package for your board in Vivado (Tools -> Vivado Store -> Boards)
 - copy the ROM image (**rom.mem**) into the **tridoracpu** directory (see above)
 - start Vivado and open the project file **tridoracpu.xpr** in the **tridoracpu** directory
@ -174,8 +128,3 @@ See the emulator [README](tridoraemu/README.md).
 - [The Mostly Missing Pascal Programming Guide](doc/pascalprogramming.md)
 More documentation is coming, as time permits.
 ## Credits
 The Tridora-CPU uses the UART from the J1 CPU by James Bowman (*uart.v*), see https://github.com/jamesbowman/j1
 The VGA framebuffer uses code from Project F by Will Green, see https://projectf.io
--- a/doc/irqctrl.md
+++ b/doc/irqctrl.md
@ -9,13 +9,12 @@ The interrupt controller uses a single register at address: $980
 |_bit_  |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00|
 |-      |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |
-|_Value_|t |t |t |t |t |t |t |t |- |- |- |- |- |p2 |p1 |p0 |
+|_Value_|t |t |t |t |t |t |t |t |- |- |- |- |- |- |p1 |p0 |
 |Bitfields|Description|
 |---------|-----------|
 | _t_     | unsigned 24 bit counter of timer ticks since reset
 | _p2_    | IRQ 2 (audio) interrupt pending if 1
 | _p1_    | IRQ 1 (timer tick) interrupt pending if 1
 | _p0_    | IRQ 0 (UART) interrupt pending if 1
--- a/doc/mem.md
+++ b/doc/mem.md
@ -22,12 +22,11 @@ The _BSEL_ and _BPLC_ instructions are designed to assist with accessing bytes w
 The byte ordering is big-endian.
 ## Accessing the I/O Area
-The I/O area uses the same word addressing in increments of four to access the registers of the I/O controllers.  In practice, only the VGA framebuffer controller and the audio controller use multiple registers.
+The I/O area organizes memory slightly different. Here, pointing out individual bytes is not very useful, so the I/O controllers use register addresses with increments of one. In practice, there is only the VGA framebuffer controller which uses multiple registers.
 For the other controllers, there is a single 32 bit register that is repeated all over the address space of the corresponding I/O slot.
 The individual I/O controllers each have a memory area of 128 bytes, so there is a maximum number of 16 I/O controllers.
-Currently, only I/O slots 0-4 are being used.
+Currently, only I/O slots 0-3 are being used.
 |I/O slot| Address | Controller |
 |--------|---------|------------|
@ -35,4 +34,3 @@ Currently, only I/O slots 0-4 are being used.
 | 1      | $880    | SPI-SD     |
 | 2      | $900    | VGA        |
 | 3      | $980    | IRQC       |
 | 4      | $A00    | TDRAUDIO   |
--- a/doc/pascalprogramming.md
+++ b/doc/pascalprogramming.md
@ -44,7 +44,7 @@ var a:array [1..3] of integer;
 	...
-	a[1] := 3; a[2] := 2; a[3] := 1;
+	a[1] := 3; a[3] := 2; a[5] := 1; 
 	for i in a do
 		writeln(i);
@ -66,7 +66,7 @@ var c:char;
 ```
 In Tridora Pascal, this syntax also works because `[ 'y', 'n' ]` will not be treated as a set literal, but as an array literal.
-The _in_ operator also works for linear arrays, so the above _if_ statement will have the same result.
+The _in_ operator also works for linear arrays, so the _if_ statement will have the same result.
 Note that the array _in_ operator will be more inefficient for larger ranges (i.e. `'A'..'z'`), but more efficient for sparse sets (i.e. `'A','z'`).
@ -103,16 +103,6 @@ Tridora-Pascal only supports the _break_ statement at the moment.
 The _exit_ statement can be used to exit the current procedure or function. If it is a function, the return value of the function is undefined if _exit_ is
 used before a return value is assigned.
 ## Dynamic Memory Allocation
 Memory allocation generally works as expected with the *new* and *dispose* special procedures. The variant of *new* with two parameters that is specified in Wirth Pascal is not supported (partial allocation of a variant record). Instead, there is a variant of *new* that has a second parameter for allocating strings (see above).
 If heap allocation fails, *new* does not return and instead causes a runtime error. To avoid this, a different special procedure called *newOrNil* can be used. This procedure sets the pointer
 variable to *niL* if heap allocation fails.
 The function *MemAvail* returns the number of free bytes on the heap. It does not guarantee that this amount of memory can be allocated with *new*, because heap space can be fragmented.
 The function *MaxAvail*, which exists in some versions of Turbo Pascal and returns the size of the largest contiguous block of available heap memory, is not (yet) implemented.
 ## I/O
 I/O handling in Tridora Pascal is mostly compatible with other Pascal dialects when reading/writing simple variables from/to the console. There are big differences when opening/reading/writing files explicitly.
@ -133,7 +123,7 @@ The implementation also has the following properties:
 - _read_/_write_ do ASCII conversion on scalar variables, records and arrays are processed as binary
 - enums and booleans are treated as integers
 - _readln_/_writeln_ operate as expected, that is, they perform _read_/_write_ and then wait for/write a newline sequence
- other file operations available are _eof_, _eoln_, _seek_ and _filepos_
+- other file operations available are _eof_, _eoln_ and _seek_
 - for error handling there is a function _IOResult_
 - terminating the program without calling _close_ on open files will lose data
@ -163,12 +153,10 @@ var f:file;
 ### Error Handling
 When an I/O error occurs, the _IOResult_ function can be called to get the error code. Unlike TP, the _IOResult_ function requires a
 file variable as a parameter. When you call _IOResult_, an error that may have occurred is considered to be _acknowledged_. If an
-error is not ackowledged and you do another I/O operation on that file, a runtime error is thrown.
+error is not ackowledged and you do another I/O operation, a runtime error is thrown.
 That means you can either write programs without checking for I/O errors, while resting assured that the program will exit if an I/O error occurs. You can also choose to check for errors with _IOResult_ if you want to avoid having runtime errors.
 If an I/O error occurs on a file, it is then considered closed. Closing a file in this state, or a file that has been closed normally, will cause a runtime error.
 The function _ErrorStr_ from the standard library takes an error code as an argument and returns the corresponding textual description as a string.
 Example:
@ -203,8 +191,7 @@ Possible error codes from _IOResult_ are:
 | 8 | IOReadOnly        | file is readonly |  |
 | 9 | IOInvalidOp       | invalid operation |  |
 | 10 | IOInvalidFormat   | invalid format | when parsing numbers with _read_ |
-| 11 | IONoMem   | not enough memory | heap allocation failed inside the standard library, e.g. open() |
+| 11 | IOUserIntr        | interrupted by user | program terminated by ^C, not visible from _IOResult_ |
 | 12 | IOUserIntr        | interrupted by user | program terminated by ^C, not visible from _IOResult_ |
 ### Read, Readln and Line Input
 In Turbo Pascal, using _read_ (and _readln_) from the console always waits until a complete line has been entered.
@ -235,85 +222,6 @@ In Wirth Pascal, labels must be numbers. Other Pascal dialects also allow normal
 Tridora-Pascal only allows identifiers as labels.
 ## Units
 Units are the method to create libraries in Tridora-Pascal, that is, codes module that can
 be reused in other programs.
 Tridora-Pascal follows the unit syntax that has been established in UCSD-Pascal and is also
 used in Turbo Pascal.
 Units are imported with the *USES* keyword, right after the *PROGRAM* statement.
 Multiple units can be imported by separating the unit names with commas.
 There are some differences: In Tridora-Pascal, the unit file does not contain the interface
 section, only the implementation section. The interface section is instead placed into a
 separate file with the extension *.inc*, without any *UNIT* or *INTERFACE* keywords.
 This file will be included by the compiler and should contain
 procedure or function declarations (as *EXTERNAL*). It can also contain *TYPE*,
 *CONST* and *VAR* statements.
 All Pascal symbols of the unit are imported into the main program. There
 is no separate namespace for units.
 ### Using an Existing Unit
 An existing unit is imported with the *USES* statement that must be placed
 immediately after the *PROGRAM* statement.
 The compiler will look for an include file with the unit name and an *.inc* extension.
 It will also
 tell the assembler to include an assembly language file for each
 unit. The filename must be the unit name plus an *.s* extension.
 Since there is no linker in Tridora-Pascal, all imported units will be
 assembled together with the main program.
 The compiler looks for unit *.inc* and *.s* files in the current volume or
 in the *SYSTEM* volume.
 ### Compiling a Unit
 A unit implementation file should start with a *UNIT* statement instead of a *PROGRAM*
 statement.
 It should be compiled, not assembled.
 When building a program that uses units, the assembler will include an assembly language
 file for each unit.
 It is possible to write units in assembly language. This is done by
 directly providing the *.s* file and creating an *.inc* file with
 the *EXTERNAL* declarations matching the assembly language
 file.
 #### Example
 ```pascal
 (* UnitExamples.pas *)
 program UnitExample;
 uses hello;
 begin
 	sayHello('unit');
 end.
 ```
 #### Example Unit Implementation File
 ```pascal
 (* hello.pas *)
 unit hello;
 implementation
 procedure sayHello(s:string);
 begin
 	writeln('hello, ', s);
 end;
 end.
 ```
 #### Example Unit Include File
 ```pascal
 (* hello.inc *)
 procedure sayHello(s:string); external;
 ```
 ## Compiler Directives
 Tridora-Pascal understands a small number of compiler directives which are introduced as usual with a comment and a dollar-sign. Both comment styles can be used.
--- a/doc/tdraudio.md
+++ b/doc/tdraudio.md
@ -1,104 +0,0 @@
 # Audio Controller
 The audio controller provides four channels of 16-bit PCM audio playback.
 It uses multiple registers starting at address $A00.
 Each of the four channels has three registers.
 For the first channel the register addresses are:
 |Address|Description|
 |-------|-----------|
 | $A00  | Control Register |
 | $A04  | Clock Divider Register |
 | $A08  | Amplitude Register |
 The register addresses for the second channel start at $A10,
 the third channel at $A20
 and the fourth channel at $A30.
 ## Reading the control register
 |_bit_  |31|30|29|28|27|26|25|24|23|22|21|20|19|18|17|16|
 |-      |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |
 |_Value_|- |- |- |- |- |- |- |- |- |-|- |- |- |- |- |- |
 |_bit_  |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00|
 |-      |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |
 |_Value_|- |- |- |- |- |- |- |- |- |- |- |i |f | e | p | c |
 |Bitfields|Description|
 |---------|-----------|
 | _i_    | interrupt is enabled for this channel when 1 |
 | _f_    | sample buffer is full when 1 |
 | _e_    | sample buffer is empty when 1 |
 | _p_     | changes from 0 to 1 and vice versa on each sample clock |
 | _c_     | channel is enabled if 1 |
 ## Writing the control register
 |_bit_  |31|30|29|28|27|26|25|24|23|22|21|20|19|18|17|16|
 |-      |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |
 |_Value_|- |- |- |- |- |- |- |- |- |-|- |- |- |- |- |- |
 |_bit_  |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00|
 |-      |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |
 |_Value_|- |- |- |- |- |- |- |- |- |- |- |i |- | - | - | c |
 |Bitfields|Description|
 |---------|-----------|
 | _c_     | enable channel if 1, disable if 0 |
 | _i_     | enable channel interrupt if 1, disable if 0 |
 ## Writing the clock divider register
 |_bit_  |31|30|29|28|27|26|25|24|23|22|21|20|19|18|17|16|
 |-      |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |
 |_Value_|d |d |d |d |d |d |d |d |d |d|d |d |d |d |d |d |
 |_bit_  |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00|
 |-      |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |
 |_Value_|d |d |d |d |d |d |d |d |d |d|d |d |d |d |d |d |
 |Bitfields|Description|
 |---------|-----------|
 | _d_     | an unsigned 32-bit value for the clock divider |
 ## Writing the amplitude register
 |_bit_  |31|30|29|28|27|26|25|24|23|22|21|20|19|18|17|16|
 |-      |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |
 |_Value_|- |- |- |- |- |- |- |- |- |-|- |- |- |- |- |- |
 |_bit_  |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00|
 |-      |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |- |
 |_Value_|a |a |a |a |a |a |a |a |a |a |a |a |a | a | a | a |
 |Bitfields|Description|
 |---------|-----------|
 | _a_     | an unsigned 16-bit value for the amplitude (sample) value with a bias of 32768 |
 ## Notes
 The clock divider specifies the number of CPU clock ticks between two samples.
 Writing to the amplitude register adds the sample value to the sample buffer. The sample buffer is organized as a FIFO with 16 elements.
 Amplitude (sample) values are represented as unsigned, biased 16-bit numbers. The bias is 32768, so given an amplitude range of 1.0 to -1.0, a 1.0 is represented by 65535, 0.0 by 32768 and -1.0 by 0.
 Interrupt processing needs to be enabled for each channel if required.
 An interrupt on any channel will be signalled to the interrupt controller
 as IRQ 2. The interrupt service routine should check all running channels
 for an emtpy buffer.
 If an audio interrupt has occured on a channel, the interrupt enable flag
 is cleared for that channel. It needs to be re-enabled in the interrupt service routine.
 Interrupts also need to be enabled on the interrupt controller,
 and re-enabled there after each interrupt.
--- a/doc/uart.md
+++ b/doc/uart.md
@ -37,7 +37,7 @@ It uses a fixed serial configuration of 115200 bps, 8 data bits, 1 stop bit, no
 ## Notes
-A 64 byte FIFO is used when receiving data.
+A 16 byte FIFO is used when receiving data.
 When reading data, each byte needs to be acknowledged by writing the _C_ flag to the UART register.
--- a/doc/vga.md
+++ b/doc/vga.md
@ -4,16 +4,13 @@ Registers
 |Name|Address|Description|
 |----|-------|-----------|
 |_FB_RA_ | $900 | Read Address |
-|_FB_WA_ | $904 | Write Address |
+|_FB_WA_ | $901 | Write Address |
-| _FB_IO_ | $908 | I/O Register |
+| _FB_IO_ | $902 | I/O Register |
-| _FB_PS_ | $90C | Palette Select |
+| _FB_PS_ | $903 | Palette Select |
-| _FB_PD_ | $910 | Palette Data |
+| _FB_PD_ | $904 | Palette Data |
-| _FB_CTL_ | $914 | Control Register |
+| _FB_CTL_ | $905 | Control Register |
-| _FB_SHIFTER_ | $918 | Shift Assist Register |
+
-| _FB_SHIFTCOUNT_ | $91C | Shift Count Register |
+
 | _FB_SHIFTERM_   | $920 | Shifted Mask Register |
 | _FB_SHIFTERSP_  | $924 | Shifter Spill Register |
 | _FB_MASKGEN_    | $928 | Mask Generator Register |
 ## Pixel Data
 Pixel data is organized in 32-bit-words. With four bits per pixel, one word
@ -84,54 +81,3 @@ The control register contains status information. It can only be read.
 The _m_ field indicates the current graphics mode. At the time of writing, it is
 always 1 which denotes a 640x400x4 mode.
 The _vb_ bit is 1 when the video signal generator is in its vertical blank phase.
 ## Shift Assist Register
 The *shift assist register* can be used to accelerate shifting pixel/bitmap data.
 Writing a word of pixel data to this register initialises the shifting process.
 After writing to the shift count register (see below), reading the shift assist
 register retrieves the shifted pixel data. 
 Writing to the shift assist register will reset the shift count.
 ## Shift Count Register
 Writing a number from 0-7 to the *shift count register* triggers shifting the
 contents of the shift assist register. Pixel data is shifted by four bits
 to the right times the shift count. Bits 31-3 of the shift count are ignored, so you can
 directly write a horizontal screen coordinate to the register.
 This register cannot be read.
 ## Shifter Mask Register
 The *shifter mask register* contains the shifted pixel data converted into
 a mask. See the *mask generator register* for an
 explanation of the mask.
 ## Shifter Spill Register
 The *shifter spill register* contains the pixel data that has
 been shifted out to the right. For example, if the shift count is two,
 the spill register contains the two rightmost pixels (bits 7-0) of
 the original pixel data, placed into the two topmost pixels (bits 31-24).
 The rest of the register is set to zero.
 ## Mask Generator Register
 The *mask generator register* creates a mask from pixel data.
 For each four bits of a pixel, the corresponding four mask bits
 are all set to one if the pixel value is not zero.
 This can be used to combine foreground and background pixel data
 where a pixel value of zero is used to indicate a transparent foreground pixel.
 Usually, the mask will be inverted with a *NOT* instruction.
 The result can then be used to clear all pixels in the background
 that are set in the foreground, using an *AND* instruction.
 As the last step, foreground and masked background data can be combined with an *OR* instruction.
 Example in hexadecimal, each digit is a pixel:
 | Pixel Data | Mask |
 |------------|------|
 | $00000000  | $00000000 |
 | $00000001  | $0000000F |
 | $0407000F  | $0F0F000F |
 | $1234ABC0  | $FFFFFFF0 |
--- a/examples/3dplot.pas
+++ b/examples/3dplot.pas
@ -1,97 +0,0 @@
 program threedeeplot;
 const w = 640;
      h = 400;
 var u0,v0:integer;
 function fun(x0,y0:real):real;
 const vscale = 50.0;
      hscale = 20.0;
 var x,y,f:real;
 begin
 	x := x0 / hscale;
 	y := y0 / hscale;
 	f := sin(sqrt(x*x + y*y));
 	fun := f * vscale;
 end;
 procedure plot;
 var maxV,minV:array [0..w] of real;
    shift:integer;
    x,y,z:integer;
    lastZ:integer;
    numLines:integer;
    i:integer;
    u,v,lastU,lastV:integer;
    color:integer;
  procedure resetCurve;
  begin
  	lastU := -1;
  	lastV := -1;
  end;
 begin
 	for i := 0 to w do
 	begin
 		maxV[i] := -10000;
 		minV[i] :=  10000;
 	end;
 	color := 1;
 	shift := 4;
 	x := 0;
 	numLines := 80;
 	u0 := w div 2;
 	v0 := h div 2;
 	for i := -(numLines div 2) to numLines do
 	begin
 		resetCurve;
 		x := i * (w div numLines);
 		for y := -w to w do
 		begin
 			z := round(fun(x,y));
 			u := round(y + u0 + i * shift);
 			v := round(-z + v0 - i * shift);
 			if (u >= 0) and (u < w) then
 			begin
 				if (v < maxV[u]) and (v > minV[u]) then
 					resetCurve
 				else
 				begin	
 					if (u >= 0) and (u < w) and (v > maxV[u]) then
 						maxV[u] := v;
 					if (u >= 0) and (u < w) and (v < minV[u]) then
 						minV[u] := v;
 					if lastZ < z then
 						color := 8
 					else
 						color := 1;
 					if (u >= w) or (u < 0) or (v >= h) or (v < 0) then
 						resetCurve
 					else
 					begin				
 						if lastU = -1 then
 							putpixel(u,v,color)
 						else
 							drawline(lastU,lastV,u,v,color);
 					end;
 					lastU := u;
 					lastV := v;
 					lastZ := z;
 				end;
 			end;
 		end;
 	end;
 end;
 begin
 	initgraphics;
 	plot;
 end.
--- a/examples/LICENSES.md
+++ b/examples/LICENSES.md
@ -7,9 +7,4 @@ https://commons.wikimedia.org/wiki/File:Ara-Zoo-Muenster-2013.jpg
 https://commons.wikimedia.org/wiki/File:Snow_leopard_portrait.jpg
 * shinkansen.pict: 投稿者が撮影, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons
 https://commons.wikimedia.org/wiki/File:0key22-86.JPG 
-* Toco_Toucan.pict: Bernard DUPONT, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons
+
 https://commons.wikimedia.org/wiki/File:Toco_Toucan_(Ramphastos_toco)_-_48153967707.jpg
 * 1911_Detroit_Electric.pict: Cullen328, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
 https://commons.wikimedia.org/wiki/File:1911_Detroit_Electric.jpg
 * ADDS-Envoy-620.pict: ADDS Envoy-1.jpg from terminals-wiki.org, CC-BY-SA 3.0
 https://terminals-wiki.org/wiki/index.php/File:ADDS_Envoy-1.jpg
--- a/examples/Toco_Toucan.pict
+++ b/examples/Toco_Toucan.pict
--- a/examples/animate.pas
+++ b/examples/animate.pas
@ -1,245 +0,0 @@
 program animate;
 uses sprites,pcmaudio;
 type PictData = record
 		magic,mode:integer;
 		palette: array [0..15] of integer;
 		pixeldata: array [0..31999] of integer;
 	end;
     Sprite = record
     	x,y:integer;
     	xdelta,ydelta:integer;
     	curFrame:integer;
     	frameCount:integer;
     	frameTime:integer;
     	frameLeft:integer;
     	moveTime:integer;
     	moveLeft:integer;
     	changed:boolean;
     	frame:array [0..3] of SpritePixels;
    end;
 var pic:PictData;
    filename:string;
    infile:file;
    ch:char;
    stickMan:Sprite;
    rocket:Sprite;
    rocket2:Sprite;
    rocket3:Sprite;
    buf:SndBufPtr;
 procedure WaitVSync; external;
 function readAudioFile(fname:string):SndBufPtr;
 var i,size:integer;
    c:char;
    buf:SndBufPtr;
    f:file;
 begin
 	open(f, fname, ModeReadOnly);
 	size := FileSize(f);
 	new(buf, size);
 	buf^ := '';
 	write('Reading ', size, ' bytes from ', fname);
 	for i := 1 to size do
 	begin
 		read(f,c);
 		AppendChar(buf^,c);
 	end;
 	writeln;
 	close(f);
 	readAudioFile := buf;	
 end;
 procedure loadPalette(var pic:PictData);
 var i:integer;
 begin
 	for i := 0 to 15 do
 		setpalette(i, pic.palette[i]);
 end;
 procedure showPic(var pic:PictData);
 begin
 	PutScreen(pic.pixeldata);
 end;
 procedure loadSpriteFrame(var aSprite:Sprite;spriteIndex:integer;
 		var sheetFile:file;sheetIndex:integer);
 begin
 	seek(sheetFile, 8 + sheetIndex * 512);
 	read(sheetFile, aSprite.frame[spriteIndex]);
 	if aSprite.frameCount <= spriteIndex then
 		aSprite.frameCount := spriteIndex + 1;
 	aSprite.curFrame := 0;
 	writeln('loaded sprite frame ', spriteIndex, ' from ', sheetIndex);
 end;
 procedure animateSprite(var aSprite:Sprite);
 var frameIndex:integer;
    frameTime,frameLeft:integer;
    moveTime,moveLeft:integer;
    ydelta:integer;
 begin
 	ydelta := aSprite.ydelta;
 	frameIndex := aSprite.curFrame;
 	frameTime := aSprite.frameTime;
 	frameLeft := aSprite.frameLeft;
 	moveTime := aSprite.moveTime;
 	moveLeft := aSprite.moveLeft;
 	frameLeft := frameLeft - 1;
 	if frameLeft <= 0 then
 	begin
 		frameIndex := frameIndex + 1;
 		frameLeft := frameTime;
 		aSprite.curFrame := frameIndex;
 		if frameIndex >= aSprite.frameCount then
 			aSprite.curFrame := 0;
 	end;
 	moveLeft := moveLeft - 1;
 	if moveLeft <= 0 then
 	begin
 		aSprite.x := aSprite.x + aSprite.xdelta;
 		aSprite.y := aSprite.y + aSprite.ydelta;
 		moveLeft := moveTime;
 		if aSprite.x > 608 then aSprite.x := 0;
 		if aSprite.ydelta <> 0 then
 		begin
 			if aSprite.y < 3 then
 				aSprite.ydelta := -aSprite.ydelta
 			else
 			if aSprite.y > 130 then
 				aSprite.ydelta := -aSprite.yDelta;
 		end;
 	end;
 	aSprite.frameLeft := frameLeft;
 	aSprite.moveLeft := moveLeft;
 end;
 procedure animLoop;
 var i:integer;
    oldX,oldY:integer;
    roldX,roldY:integer;
    r2oldX,r2oldY:integer;
    r3oldX,r3oldY:integer;
 begin
 	stickMan.x := 0;
 	stickMan.y := 205;
 	stickMan.frameTime := 6;
 	stickMan.frameLeft := stickMan.frameTime;
 	stickMan.curFrame := 0;
 	stickMan.xdelta := 2;
 	stickMan.ydelta := 0;
 	stickMan.moveTime := 2;
 	stickman.moveLeft := stickMan.moveTime;
 	rocket.x := 0;
 	rocket.y := 50;
 	rocket.frameTime := 5;
 	rocket.frameLeft := rocket.frameTime;
 	rocket.curFrame := 0;
 	rocket.xdelta := 3;
 	rocket.ydelta := 1;
 	rocket.moveTime := 1;
 	rocket.moveLeft := rocket.moveTime;
 	rocket2.x := 50;
 	rocket2.y := 190;
 	rocket2.frameTime := 5;
 	rocket2.frameLeft := rocket2.frameTime;
 	rocket2.curFrame := 1;
 	rocket2.xdelta := 3;
 	rocket2.ydelta := 0;
 	rocket2.moveTime := 1;
 	rocket2.moveLeft := rocket2.moveTime;
 	rocket3.x :=100;
 	rocket3.y := 90;
 	rocket3.frameTime := 5;
 	rocket3.frameLeft := rocket3.frameTime;
 	rocket3.curFrame := 2;
 	rocket3.xdelta := 3;
 	rocket3.ydelta := -1;
 	rocket3.moveTime := 1;
 	rocket3.moveLeft := rocket3.moveTime;
 	while not ConAvail do
 	begin
 		oldX := stickMan.x;
 		oldY := stickMan.y;
 		roldX := rocket.x;
 		roldY := rocket.y;
 		r2oldX := rocket2.x;
 		r2oldY := rocket2.y;
 		r3oldX := rocket3.x;
 		r3oldY := rocket3.y;
 		PutSprite(roldX, roldY, rocket.frame[rocket.curFrame]);
 		PutSprite(r2oldX, r2oldY, rocket2.frame[rocket2.curFrame]);
 		PutSprite(r3oldX, r3oldY, rocket3.frame[rocket3.curFrame]);
 		PutSprite(oldX, oldY, stickMan.frame[stickMan.curFrame]);
 		animateSprite(rocket);
 		animateSprite(rocket2);
 		animateSprite(rocket3);
 		animateSprite(stickMan);
 		Delay(10);
 		WaitVSync;
 		UndrawSprite(oldX, oldY, pic.pixeldata);
 		UndrawSprite(roldX, roldY, pic.pixeldata);
 		UndrawSprite(r2oldX, r2oldY, pic.pixeldata);
 		UndrawSprite(r3oldX, r3oldY, pic.pixeldata);
 	end;
 end;
 begin
 	filename := 'background.pict';
 	open(infile, filename, ModeReadonly);
 	read(infile, pic);
 	close(infile);
 	writeln('magic: ', pic.magic, ' mode:', pic.mode);
 	loadPalette(pic);
 	showPic(pic);
 	open(infile, 'walking.sprt', ModeReadOnly);
 	loadSpriteFrame(stickMan, 0, infile, 0);
 	loadSpriteFrame(stickMan, 1, infile, 1);
 	loadSpriteFrame(stickMan, 2, infile, 2);
 	loadSpriteFrame(stickMan, 3, infile, 3);
 	close(infile);
 	open(infile, 'rocket.sprt', ModeReadOnly);
 	loadSpriteFrame(rocket, 0, infile, 0);
 	loadSpriteFrame(rocket, 1, infile, 1);
 	loadSpriteFrame(rocket, 2, infile, 2);
 	loadSpriteFrame(rocket, 3, infile, 3);
 	close(infile);
 	rocket2 := rocket;
 	rocket3 := rocket;
 	buf := readAudioFile('footsteps.tdrau');
 	SampleQStart(buf, true, 16000);
 	animLoop;
 	SampleQStop;
 	dispose(buf);
 end.
--- a/examples/background.pict
+++ b/examples/background.pict
--- a/examples/benchmarks.pas
+++ b/examples/benchmarks.pas
@ -1,299 +0,0 @@
 {$H350}
 program benchmarks;
 var starttime:DateTime;
    endtime:DateTime;
 procedure startBench(name:string);
 begin
 	write(name:35, ' ');
 	starttime := GetTime;
 end;
 procedure endBench;
 var secDelta, minDelta, hourDelta:integer;
  procedure write2Digits(i:integer);
  begin
  	if i < 10 then
  		write('0');
  	write(i);
  end;
 begin
 	endtime := GetTime;
 	hourDelta := endtime.hours - starttime.hours;
 	minDelta  := endtime.minutes - starttime.minutes;
 	secDelta  := endtime.seconds - starttime.seconds;
 	if secDelta < 0 then
 	begin
 		secDelta := 60 + secDelta;
 		minDelta := minDelta - 1;
 	end;
 	if minDelta < 0 then
 	begin
 		minDelta := 60 + minDelta;
 		hourDelta := hourDelta - 1;
 	end;
 	write2Digits(hourDelta);
 	write(':');
 	write2Digits(minDelta);
 	write(':');
 	write2Digits(secDelta);
 	writeln;
 end;
 procedure bench0;
 var i:integer;
 begin
 	startBench('empty loop 10M');
 	for i := 1 to 10000000 do;
 	endBench;
 end;
 procedure bench1;
 var i:integer;
    v:integer;
 begin
 	startBench('write variable 10M');
 	for i := 1 to 10000000 do
 		v := 0;
 	endBench;
 end;
 procedure bench2;
 var i:integer;
    v,r:integer;
 begin
 	v := 4711;
 	startBench('read variable 10M');
 	for i := 1 to 10000000 do
 		r := v;
 	endBench;
 end;
 procedure bench3;
 var i:integer;
    a,b:integer;
 begin
 	a := 0;
 	b := 100;
 	startBench('integer addition 10M');
 	for i := 1 to 10000000 do
 		a := b + i;
 	endBench;	
 end;
 procedure bench4;
 var i:integer;
    a,b:real;
 begin
 	a := 0.0;
 	b := 100.0;
 	startBench('real addition 1M');
 	for i := 1 to 1000000 do
 		a := b + i;
 	endBench;
 end;
 procedure bench5;
 var i:integer;
    a,b:integer;
 begin
 	a := 0;
 	b := 100;
 	startBench('integer multiplication 1M');
 	for i := 1 to 1000000 do
 		a := b * i;
 	endBench;	
 end;
 procedure bench6;
 var i:integer;
    a,b:real;
 begin
 	a := 0;
 	b := 100;
 	startBench('real multiplication 1M');
 	for i := 1 to 1000000 do
 		a := b * i;
 	endBench;
 end;
 procedure bench7;
 var i:integer;
    a,b:integer;
 begin
 	a := 0;
 	b := 31415926;
 	startBench('integer division 1M');
 	for i := 1 to 1000000 do
 		a := b div i;
 	endBench;
 end;
 procedure bench8;
 var i:integer;
    a,b,c:real;
 begin
 	a := 0;
 	b := 31415926.0;
 	startBench('real division 1M');
 	for i := 1 to 1000000 do
 		a := b / i;
 	endBench;
 end;
 procedure bench9;
 var i,j:integer;
    s:string[100];
    c:char;
 begin
 	s := '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn';
 	startBench('string indexing 1M');
 	for i := 1 to 100000 do
 		for j := 1 to 100 do
 			c := s[j];
 	endBench;
 end;
 procedure bench10;
 var i:integer;
    s:string[100];
    c,d:char;
 begin
 	s := '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn';
 	startBench('string iteration 1M');
 	for i := 1 to 100000 do
 		for c in s do
 			d := c;
 	endBench;
 end;
 procedure bench11;
 var ptr: ^array[0..255] of integer;
    dummy1,dummy2,dummy3: ^array[0..127] of boolean;
    i:integer;
 begin
 	new(dummy1);
 	new(dummy2);
 	new(dummy3);
 	dispose(dummy1);
 	startBench('new/dispose 1k 1M');
 	for i := 1 to 1000000 do
 	begin
 		new(ptr);
 		dispose(ptr);
 	end;
 	endBench;
 	dispose(dummy2);
 	dispose(dummy3);
 end;
 procedure bench12;
 var ptr: ^array[0..32767] of integer;
    dummy1,dummy2,dummy3: ^array[0..127] of boolean;
    i:integer;
 begin
 	new(dummy1);
 	new(dummy2);
 	new(dummy3);
 	dispose(dummy1);
 	startBench('new/dispose 128k 1M');
 	for i := 1 to 1000000 do
 	begin
 		new(ptr);
 		dispose(ptr);
 	end;
 	endBench;
 	dispose(dummy2);
 	dispose(dummy3);
 end;
 procedure bench13;
 var ptr1: ^array[0..255] of integer;
    ptr2: ^array[0..255] of integer;
    i:integer;
 begin
 	new(ptr1);
 	new(ptr2);
 	startBench('array copy 1k 10K');
 	for i := 1 to 10000 do
 		ptr1^ := ptr2^;
 	endBench;
 	dispose(ptr1);
 	dispose(ptr2);
 end;
 procedure bench14;
 var ptr1: ^array[0..32767] of integer;
    ptr2: ^array[0..32767] of integer;
    i:integer;
 begin
 	new(ptr1);
 	new(ptr2);
 	startBench('array copy 128k 1K');
 	for i := 1 to 1000 do
 		ptr1^ := ptr2^;
 	endBench;
 	dispose(ptr1);
 	dispose(ptr2);
 end;
 procedure bench15;
 var i,j:integer;
    a:real;
 begin
 	startBench('exp() 10K');
 	for i := 1 to 1000 do
 		for j := 1 to 10 do
 			a := exp(j);
 	endBench;
 end;
 procedure bench16;
 var i,j:integer;
    a,b:real;
 begin
 	startBench('cos() 10K');
 	b := 0.0;
 	for i := 1 to 10000 do
 	begin
 		a := cos(b);
 		b := b + 0.0001;
 	end;
 	endBench;
 end;
 begin
 	bench0;
 	bench1;
 	bench2;
 	bench3;
 	bench4;
 	bench5;
 	bench6;
 	bench7;
 	bench8;
 	bench9;
 	bench10;
 	bench11;
 	bench12;
 	bench13;
 	bench14;
 	bench15;
 	bench16;
 end.
--- a/examples/benchmarks.results.text
+++ b/examples/benchmarks.results.text
@ -1,196 +0,0 @@
 ------------------------
 Arty-A7-35T
 83MHz, 64KB SRAM, 256MB DRAM
 Running benchmarks.prog
                     empty loop 10M 00:00:09
                 write variable 10M 00:00:10
                  read variable 10M 00:00:12
               integer addition 10M 00:00:16
                   real addition 1M 00:00:27
          integer multiplication 1M 00:01:07
             real multiplication 1M 00:00:58
                integer division 1M 00:01:44
                   real division 1M 00:01:06
                 string indexing 1M 00:00:27
                string iteration 1M 00:00:11
                  new/dispose 1k 1M 00:00:19
                new/dispose 128k 1M 00:00:19
                  array copy 1k 10K 00:00:02
                 array copy 128k 1K 00:00:44
                          exp() 10K 00:00:29
                          cos() 10K 00:00:06
 --------------------------------------
 Arty-A7-35T
 83MHz, 64KB SRAM, 256MB DRAM
 running in DRAM (except corelib, stdlib, runtime)
 Running benchmarks.prog
                     empty loop 10M 00:00:30
                 write variable 10M 00:00:37
                  read variable 10M 00:00:40
               integer addition 10M 00:00:48
                   real addition 1M 00:00:31
          integer multiplication 1M 00:01:11
             real multiplication 1M 00:01:03
                integer division 1M 00:01:48
                   real division 1M 00:01:11
                 string indexing 1M 00:01:13
                string iteration 1M 00:00:47
                  new/dispose 1k 1M 00:00:27
                new/dispose 128k 1M 00:00:27
                  array copy 1k 10K 00:00:03
                 array copy 128k 1K 00:00:44
                          exp() 10K 00:00:29
                          cos() 10K 00:00:06
 --------------------------------------
 Arty-A7-35T
 76.92MHz, 64KB SRAM, 256MB DRAM
 running in DRAM (except corelib, stdlib, runtime)
 Running benchmarks.prog
                     empty loop 10M 00:00:32
                 write variable 10M 00:00:40
                  read variable 10M 00:00:43
               integer addition 10M 00:00:52
                   real addition 1M 00:00:34
          integer multiplication 1M 00:01:17
             real multiplication 1M 00:01:08
                integer division 1M 00:01:57
                   real division 1M 00:01:17
                 string indexing 1M 00:01:19
                string iteration 1M 00:00:51
                  new/dispose 1k 1M 00:00:29
                new/dispose 128k 1M 00:00:30
                  array copy 1k 10K 00:00:03
                 array copy 128k 1K 00:00:48
                          exp() 10K 00:00:32
                          cos() 10K 00:00:06
 --------------------------------------
 Arty-A7-35T
 76.92MHz, 64KB SRAM, 256MB DRAM, 16B instruction cache
 running in DRAM (except corelib, stdlib, runtime)
 Running benchmarks.prog
                     empty loop 10M 00:00:16
                 write variable 10M 00:00:17
                  read variable 10M 00:00:19
               integer addition 10M 00:00:24
                   real addition 1M 00:00:30
          integer multiplication 1M 00:01:14
             real multiplication 1M 00:01:05
                integer division 1M 00:01:53
                   real division 1M 00:01:13
                 string indexing 1M 00:00:41
                string iteration 1M 00:00:21
                  new/dispose 1k 1M 00:00:25
                new/dispose 128k 1M 00:00:26
                  array copy 1k 10K 00:00:03
                 array copy 128k 1K 00:00:48
                          exp() 10K 00:00:32
                          cos() 10K 00:00:06
 --------------------------------------
 Arty-A7-35T
 76.92MHz, 64KB SRAM, 256MB DRAM,
  16B instruction cache, 16B wt data cache
 running in SRAM
 Running benchmarks.prog
                     empty loop 10M 00:00:07
                 write variable 10M 00:00:17
                  read variable 10M 00:00:20
               integer addition 10M 00:00:20
                   real addition 1M 00:00:28
          integer multiplication 1M 00:01:11
             real multiplication 1M 00:00:59
                integer division 1M 00:01:36
                   real division 1M 00:01:05
                 string indexing 1M 00:00:39
                string iteration 1M 00:00:19
                  new/dispose 1k 1M 00:00:19
                new/dispose 128k 1M 00:00:19
                  array copy 1k 10K 00:00:03
                 array copy 128k 1K 00:00:39
                          exp() 10K 00:00:26
                          cos() 10K 00:00:05
 --------------------------------------
 Arty-A7-35T
 76.92MHz, 64KB SRAM, 256MB DRAM,
  16B instruction cache, 16B wb data cache
 running in SRAM
 Running benchmarks.prog
                     empty loop 10M 00:00:04
                 write variable 10M 00:00:11
                  read variable 10M 00:00:18
               integer addition 10M 00:00:18
                   real addition 1M 00:00:27
          integer multiplication 1M 00:00:49
             real multiplication 1M 00:00:58
                integer division 1M 00:01:06
                   real division 1M 00:01:04
                 string indexing 1M 00:00:36
                string iteration 1M 00:00:19
                  new/dispose 1k 1M 00:00:18
                new/dispose 128k 1M 00:00:18
                  array copy 1k 10K 00:00:03
                 array copy 128k 1K 00:00:39
                          exp() 10K 00:00:25
                          cos() 10K 00:00:05
 --------------------------------------
 Arty-A7-35T
 76.92MHz, 32KB SRAM, 256MB DRAM,
  16B instruction cache, 16B wb data cache
 running in SRAM
 Running benchmarks.prog
                     empty loop 10M 00:00:04
                 write variable 10M 00:00:11
                  read variable 10M 00:00:18
               integer addition 10M 00:00:18
                   real addition 1M 00:00:27
          integer multiplication 1M 00:00:49
             real multiplication 1M 00:00:58
                integer division 1M 00:01:06
                   real division 1M 00:01:04
                 string indexing 1M 00:00:36
                string iteration 1M 00:00:19
                  new/dispose 1k 1M 00:00:18
                new/dispose 128k 1M 00:00:18
                  array copy 1k 10K 00:00:03
                 array copy 128k 1K 00:00:39
                          exp() 10K 00:00:25
                          cos() 10K 00:00:05
 --------------------------------------------
 Arty-A7-35T
 76.92MHz, 64KB SRAM, 256MB DRAM,
  16B instruction cache, 16B wb data cache
 running in DRAM (except corelib, stdlib, runtime)
 Running benchmarks.prog
                     empty loop 10M 00:00:10
                 write variable 10M 00:00:11
                  read variable 10M 00:00:11
               integer addition 10M 00:00:13
                   real addition 1M 00:00:27
          integer multiplication 1M 00:00:35
             real multiplication 1M 00:00:43
                integer division 1M 00:01:05
                   real division 1M 00:00:51
                 string indexing 1M 00:00:36
                string iteration 1M 00:00:20
                  new/dispose 1k 1M 00:00:23
                new/dispose 128k 1M 00:00:23
                  array copy 1k 10K 00:00:03
                 array copy 128k 1K 00:00:48
                          exp() 10K 00:00:28
                          cos() 10K 00:00:04
--- a/examples/default-palette.pal
+++ b/examples/default-palette.pal
@ -1,19 +0,0 @@
 JASC-PAL
 0100
 16
 0 0 0
 255 255 255
 255 0 0
 0 255 0
 0 0 255
 0 255 255
 255 0 255
 255 255 0
 127 127 127
 160 160 160
 127 0 0
 0 127 0
 0 0 127
 0 127 127
 127 0 127
 127 127 0
--- a/examples/fastfire.inc
+++ b/examples/fastfire.inc
@ -1,5 +0,0 @@
 const FIREWIDTH = 319; FIREHEIGHT = 79; (* keep in sync with fastfire.s! *)
 type FireBuf = array [0..FIREHEIGHT, 0..FIREWIDTH] of integer;
 procedure FastFireUpdate(var f:FireBuf); external;
 procedure FastFireDraw(var f:FireBuf;screenx, screeny:integer); external;
--- a/examples/fastfire.s
+++ b/examples/fastfire.s
@ -1,326 +0,0 @@
 	; width and height of the fire cell matrix
 	; Be sure to sync this with fastfire.inc!
 	.EQU FIREWIDTH 319
 	.EQU FIREHEIGHT 79
 	;
 	; The cell matrix actually has one column
 	; and one row more than FIREWIDTH and
 	; FIREHEIGHT to handle the negative
 	; X offsets when calculating new
 	; cell values.
 	; Likewise, there is one more row.
 	; So rows are processed from 0 to FIREHEIGHT - 2
 	; and columms from 1 to FIREWIDTH - 1.
 	; cells considered for calculating new
 	; value for cell O (reference cells):
 	;	.....O......
 	;	....123.....
 	;	.....4......
 ; args: pointer to fire cell buffer
 	.EQU FF_ROW_COUNT 0
 	.EQU FF_COL_COUNT 4
 	.EQU FF_ROW_OFFS 8
 	.EQU FF_OFFS1 12
 	.EQU FF_OFFS2 16
 	.EQU FF_OFFS3 20
 	.EQU FF_OFFS4 24
 	.EQU FF_CELL_PTR 28
 	.EQU FF_FS 32
 FASTFIREUPDATE:
 	FPADJ -FF_FS
 	STORE FF_CELL_PTR
 	LOADC FIREHEIGHT-1
 	STORE FF_ROW_COUNT
 	; calculate offsets for reference cells
 	LOADC FIREWIDTH+1
 	SHL 2
 	DUP
 	STORE FF_ROW_OFFS	; offset to next row: WIDTH*4
 	DEC 4			; offset to cell 1: row offset - 4
 	DUP
 	STORE FF_OFFS1
 	INC 4
 	DUP
 	STORE FF_OFFS2		; offset to cell 2: + 4
 	INC 4
 	STORE FF_OFFS3		; offset to cell 3: + 4
 	LOAD FF_ROW_OFFS
 	SHL 1			; offset to cell 4: row offset * 2
 	STORE FF_OFFS4
 	; start at column 1
 	LOAD FF_CELL_PTR
 	INC 4
 	STORE FF_CELL_PTR
 FF_ROW:
 	LOADC FIREWIDTH-1
 	STORE FF_COL_COUNT
 FF_COL:
 	LOAD FF_CELL_PTR
 	LOAD FF_OFFS1
 	ADD
 	LOADI
 	LOAD FF_CELL_PTR
 	LOAD FF_OFFS2
 	ADD
 	LOADI
 	LOAD FF_CELL_PTR
 	LOAD FF_OFFS3
 	ADD
 	LOADI
 	LOAD FF_CELL_PTR
 	LOAD FF_OFFS4
 	ADD
 	LOADI
 	ADD
 	ADD
 	ADD
 	SHR
 	SHR
 	; if new cell value > 0, subtract 1 to cool down
 	DUP
 	CBRANCH.Z FF_SKIP
 	DEC 1
 FF_SKIP:
 	LOAD FF_CELL_PTR	; load cell ptr
 	SWAP			; swap with new value
 	STOREI 4		; store with postincrement
 	STORE FF_CELL_PTR	; save new ptr value
 	LOAD FF_COL_COUNT	; decrement column count
 	DEC 1
 	DUP
 	STORE FF_COL_COUNT
 	CBRANCH.NZ FF_COL	; loop if col count <> 0
 	; at the end of a row, go to next row
 	; by adding 8 to the cell pointer,
 	; skipping the first cell of the next row
 	LOAD FF_CELL_PTR
 	INC 8
 	STORE FF_CELL_PTR
 	LOAD FF_ROW_COUNT	; decrement row count
 	DEC 1
 	DUP
 	STORE FF_ROW_COUNT
 	CBRANCH.NZ FF_ROW	; loop if row count <> 0
 FF_EXIT:
 	FPADJ FF_FS
 	RET
 ; framebuffer controller registers
 	.EQU FB_RA $900
 	.EQU FB_WA $904
 	.EQU FB_IO $908
 	.EQU FB_PS $90C
 	.EQU FB_PD $910
 	.EQU FB_CTL $914
 	.EQU WORDS_PER_LINE 80
 ; fire width in vmem words (strict left-to-right evaluation)
 	.EQU FFD_ROW_WORDS 1 + FIREWIDTH / 8
 ; draw all fire cells
 ; args: pointer to fire cell buffer, screen x, screen y
 	.EQU FFD_CELL_PTR 0
 	.EQU FFD_X 4
 	.EQU FFD_Y 8
 	.EQU FFD_ROW_COUNT 12
 	.EQU FFD_ROW_WORDCOUNT 16
 	.EQU FFD_VMEM_PTR 20
 	.EQU FFD_FS 24
 FASTFIREDRAW:
 	FPADJ -FFD_FS
 	STORE FFD_Y
 	STORE FFD_X
 	STORE FFD_CELL_PTR
 	; calculate video memory addr
 	; addr = y * 80 + X / 8
 	LOAD FFD_Y
 	SHL 2	; y * 16
 	SHL 2
 	DUP
 	SHL 2	; + y * 64
 	ADD	; = y * 80
 	LOAD FFD_X
 	SHR
 	SHR
 	SHR
 	ADD	; + x / 8
 	DUP
 	STORE FFD_VMEM_PTR
 	LOADC FB_WA	; set vmem write address
 	SWAP
 	STOREI
 	DROP
 	LOADC FIREHEIGHT + 1
 	STORE FFD_ROW_COUNT
 FFD_ROW:
 	LOADC FFD_ROW_WORDS
 	STORE FFD_ROW_WORDCOUNT
 	LOADC FB_WA	; set vmem write address
 	LOAD FFD_VMEM_PTR
 	STOREI
 	DROP
 FFD_WORD:
 	LOAD FFD_CELL_PTR	; load cell ptr
 	LOADC 0			; vmem word, start with 0
 	; leftmost pixel (0)
 	OVER	;			[ cptr, vmemw, cptr ]
 	LOADI	; load cell value	[ cptr, vmemw, cellval ]
 	SHR	; scale it down (from 7 bits to 4)
 	SHR
 	SHR	;			[ cptr, vmemw, cellval shr 3 ]
 	OR	;			[ cptr, vmemw ]
 	SWAP	;			[ vmemw, cptr ] 
 	INC 4	; increment cell ptr on stack [ vmemw, cptr + 4 ]
 	SWAP	;			[ cptr + 4, vmemw ]
 	SHL 2			; move bits to left for next pixel
 	SHL 2
 	; pixel 1
 	OVER
 	LOADI	; load cell value
 	SHR	; scale it down (from 7 bits to 4)
 	SHR
 	SHR
 	OR
 	SWAP
 	INC 4	; increment cell ptr on stack
 	SWAP
 	SHL 2			; move bits to left for next pixel
 	SHL 2
 	; pixel 2
 	OVER
 	LOADI	; load cell value
 	SHR	; scale it down (from 7 bits to 4)
 	SHR
 	SHR
 	OR
 	SWAP
 	INC 4	; increment cell ptr on stack
 	SWAP
 	SHL 2			; move bits to left for next pixel
 	SHL 2
 	; pixel 3
 	OVER
 	LOADI	; load cell value
 	SHR	; scale it down (from 7 bits to 4)
 	SHR
 	SHR
 	OR
 	SWAP
 	INC 4	; increment cell ptr on stack
 	SWAP
 	SHL 2			; move bits to left for next pixel
 	SHL 2
 	; pixel 4
 	OVER
 	LOADI	; load cell value
 	SHR	; scale it down (from 7 bits to 4)
 	SHR
 	SHR
 	OR
 	SWAP
 	INC 4	; increment cell ptr on stack
 	SWAP
 	SHL 2			; move bits to left for next pixel
 	SHL 2
 	; pixel 5
 	OVER
 	LOADI	; load cell value
 	SHR	; scale it down (from 7 bits to 4)
 	SHR
 	SHR
 	OR
 	SWAP
 	INC 4	; increment cell ptr on stack
 	SWAP
 	SHL 2			; move bits to left for next pixel
 	SHL 2
 	; pixel 6
 	OVER
 	LOADI	; load cell value
 	SHR	; scale it down (from 7 bits to 4)
 	SHR
 	SHR
 	OR
 	SWAP
 	INC 4	; increment cell ptr on stack
 	SWAP
 	SHL 2			; move bits to left for next pixel
 	SHL 2
 	; pixel 7
 	OVER
 	LOADI	; load cell value
 	SHR	; scale it down (from 7 bits to 4)
 	SHR
 	SHR
 	OR
 	SWAP
 	INC 4	; increment cell ptr on stack
 	SWAP
 	; store word to vmem
 	; vmem write addr will autoincrement
 	LOADC FB_IO
 	SWAP
 	STOREI
 	DROP
 	STORE FFD_CELL_PTR
 	; prepare for next word
 	LOAD FFD_ROW_WORDCOUNT
 	DEC 1
 	DUP
 	STORE FFD_ROW_WORDCOUNT
 	CBRANCH.NZ FFD_WORD
 	; prepare for next row
 	LOAD FFD_VMEM_PTR
 	LOADC WORDS_PER_LINE
 	ADD
 	STORE FFD_VMEM_PTR	
 	LOAD FFD_ROW_COUNT
 	DEC 1
 	DUP
 	STORE FFD_ROW_COUNT
 	CBRANCH.NZ FFD_ROW		
 FFD_EXIT:
 	FPADJ FFD_FS
 	RET
--- a/examples/fire.pas
+++ b/examples/fire.pas
@ -1,76 +0,0 @@
 {$H1}
 {$S2}
 program fire;
 const MAXX = 30;
      MAXY = 50;
 var firebuf: array [0..MAXY, 0..MAXX] of integer;
    firepalette: array [0..15] of integer =
    	( $FFA, $FF8, $FF4, $FF0, $FE0, $FD0, $FA0, $F90,
    	  $F00, $E00, $D00, $A00, $800, $600, $300, $000);
    x,y:integer;
 procedure createPalette;
 var i:integer;
 begin
 	for i := 15 downto 0 do
 		setpalette(15 - i, firepalette[i]);
 end;
 procedure fireItUp;
 var x,y:integer;
 begin
 	y := MAXY - 1;
 	for x := 1 to MAXX - 1 do
 		firebuf[y, x] := random and 127;
 end;
 procedure updateFire;
 var i,x,y:integer;
 begin
 	for y := 0 to MAXY - 2 do
 		for x := 1 to MAXX - 1 do
 		begin
 			i :=
 				((firebuf[y + 1, x - 1]
 				+ firebuf[y + 1, x]
 				+ firebuf[y + 1, x + 1]
 				+ firebuf[y + 2, x])
 				) shr 2;
 			if i > 0 then
 				i := i - 1;
 			firebuf[y, x] := i;
 		end;
 end;
 procedure drawFire;
 var x, y, col:integer;
 begin
 	for y := 0 to MAXY - 1 do
 	begin
 		x := 0;
 		for col in firebuf[y] do
 		begin
 			putpixel(300 + x, 150 + y, col shr 3);
 			x := x + 1;
 		end;
 	end;
 end;
 begin
 	randomize;
 	initgraphics;
 	createPalette;
 	while not conavail do
 	begin
 		fireItUp;
 		updateFire;
 		drawFire;
 	end;
 	for y := 0 to MAXY do
 	begin
 		x := firebuf[y, 10];
 		drawline(0, y, x, y, 1);
 	end;
 end.
--- a/examples/fire2.pas
+++ b/examples/fire2.pas
@ -1,84 +0,0 @@
 {$H1}
 {$S1}
 program fire2;
 uses fastfire;
 const MAXX = FIREWIDTH;
      MAXY = FIREHEIGHT;
 var firecells: FireBuf;
    firepalette: array [0..15] of integer =
    	{ ( $FFA, $FF8, $FF4, $FF0, $FE0, $FD0, $FA0, $F90,
    	  $F00, $E00, $D00, $A00, $800, $600, $300, $000); }
    	( $FFA, $FFA, $FFA, $FFA, $FF0, $FF0, $FF0, $FF0,
    	  $FF0, $FD0, $FA0, $C00, $A00, $700, $400, $000);
    x,y:integer;
 procedure createPalette;
 var i:integer;
 begin
 	for i := 15 downto 0 do
 		setpalette(15 - i, firepalette[i]);
 end;
 procedure fireItUp;
 var x,y:integer;
 begin
 	y := MAXY - 1;
 	for x := 1 to MAXX - 1 do
 		firecells[y, x] := random and 127;
 end;
 procedure updateFire;
 var i,x,y:integer;
 begin
 	for y := 0 to MAXY - 2 do
 		for x := 1 to MAXX - 1 do
 		begin
 			i :=
 				((firecells[y + 1, x - 1]
 				+ firecells[y + 1, x]
 				+ firecells[y + 1, x + 1]
 				+ firecells[y + 2, x])
 				) shr 2;
 			if i > 0 then
 				i := i - 1;
 			firecells[y, x] := i;
 		end;
 end;
 procedure drawFire;
 var x, y, col:integer;
 begin
 	for y := 0 to MAXY - 1 do
 	begin
 		x := 0;
 		for col in firecells[y] do
 		begin
 			putpixel(100 + x, 150 + y, col shr 3);
 			x := x + 1;
 		end;
 	end;
 end;
 begin
 	randomize;
 	initgraphics;
 	createPalette;
 	while not conavail do
 	begin
 		fireItUp;
 		FastFireUpdate(firecells);
 		{ updateFire; }
 		FastFireDraw(firecells, 160, 100);
 		{ drawFire; }
 	end;
 	for y := 0 to MAXY do
 	begin
 		x := firecells[y, 10];
 		drawline(0, y, x, y, 1);
 	end;
 end.
--- a/examples/graphbench.pas
+++ b/examples/graphbench.pas
@ -1,125 +0,0 @@
 program graphbench;
 uses sprites;
 var starttime,endtime:DateTime;
    spriteData:SpritePixels;
 procedure readSpriteData(filename:string);
 var f:file;
 begin
 	open(f,filename,ModeReadOnly);
 	seek(f,8); (* skip file header *)
 	read(f,spriteData);
 	close(f);
 end;
 procedure startBench(name:string);
 begin
 	write(name:20, ' ');
 	starttime := GetTime;
 end;
 procedure endBench;
 var secDelta, minDelta, hourDelta:integer;
  procedure write2Digits(i:integer);
  begin
 	if i < 10 then
 		write('0');
 	write(i);
  end;
 begin
 	endTime := GetTime;
 	hourDelta := endtime.hours - starttime.hours;
 	minDelta  := endtime.minutes - starttime.minutes;
 	secDelta  := endtime.seconds - starttime.seconds;
 	if secDelta < 0 then
 	begin
 		secDelta := 60 + secDelta;
 		minDelta := minDelta - 1;
 	end;
 	if minDelta < 0 then
 	begin
 		minDelta := 60 + minDelta;
 		hourDelta := hourDelta - 1;
 	end;
 	write2Digits(hourDelta);
 	write(':'); write2Digits(minDelta);
 	write(':'); write2Digits(secDelta);
 	writeln;
 end;
 function randint(lessthan:integer):integer;
 var r:integer;
 begin
 	r := random and 511;
 	if r >= lessthan then
 		r := r - lessthan;
 	randint := r;
 end;
 procedure drawsprites(count:integer);
 var i,col,x,y:integer;
 begin
 	col := 1;
 	for i := 1 to count do
 	begin
 		x := randint(350);
 		y := randint(350);
 		PutSprite(x,y,spriteData);
 		col := col + 1;
 		if col > 15 then col := 1;
 	end;
 end;
 procedure drawlines(count:integer);
 var i,col,x1,y1,x2,y2:integer;
 begin
 	col := 1;
 	for i := 1 to count do
 	begin
 		x1 := randint(500);
 		y1 := randint(400);
 		x2 := randint(500);
 		y2 := randint(400);
 		DrawLine(x1,y1,x2,y2,col);
 		col := col + 1;
 		if col > 15 then col := 1;
 	end;
 end;
 procedure drawpoints(count:integer);
 var i,col,x,y:integer;
 begin
 	col := 1;
 	for i := 1 to count do
 	begin
 		x := randint(500);
 		y := randint(400);
 		PutPixel(x,y,col);
 		col := col + 1;
 		if col > 15 then col := 1;
 	end;
 end;
 begin
 	readSpriteData('sprite-testcard.sprt');
 	InitGraphics;
 	startBench('points 200K');
 	drawpoints(200000);
 	endBench;
 	InitGraphics;
 	startBench('lines 10K');
 	drawlines(10000);
 	endBench;
 	InitGraphics;
 	startBench('sprites 50K');
 	drawsprites(50000);
 	endBench;
 end.
--- a/examples/grey.pict
+++ b/examples/grey.pict
--- a/examples/pcmtest.pas
+++ b/examples/pcmtest.pas
@ -1,56 +0,0 @@
 {$H2560}
 program pcmtest2;
 uses pcmaudio;
 var filename:string;
    buf:SndBufPtr;
    sampleRate:integer;
    err:integer;
    done:boolean;
    c:char;
 function readAudioFile(fname:string):SndBufPtr;
 var i,size:integer;
    c:char;
    buf:SndBufPtr;
    f:file;
 begin
 	open(f, fname, ModeReadOnly);
 	size := FileSize(f);
 	new(buf, size);
 	buf^ := '';
 	write('Reading ', size, ' bytes...');
 	for i := 1 to size do
 	begin
 		read(f,c);
 		AppendChar(buf^,c);
 	end;
 	writeln;
 	close(f);
 	readAudioFile := buf;
 end;
 begin
 	if ParamCount > 0 then
 		filename := ParamStr(1)
 	else
 	begin
 		write('Filename> ');
 		readln(filename);
 	end;
 	err := 1;
 	if ParamCount > 1 then
 		val(ParamStr(2), sampleRate, err);
 	if err > 0 then
 		sampleRate := 22050;
 	buf := readAudioFile(filename);
 	PlaySample(buf, sampleRate);
 	dispose(buf);
 end.
--- a/examples/pcmtest2.pas
+++ b/examples/pcmtest2.pas
@ -1,74 +0,0 @@
 {$H2560}
 program pcmtest2;
 uses pcmaudio;
 var filename:string;
    buf:SndBufPtr;
    sampleRate:integer;
    err:integer;
    done:boolean;
    c:char;
 function readAudioFile(fname:string):SndBufPtr;
 var i,size:integer;
    c:char;
    buf:SndBufPtr;
    f:file;
 begin
 	open(f, fname, ModeReadOnly);
 	size := FileSize(f);
 	new(buf, size);
 	buf^ := '';
 	write('Reading ', size, ' bytes...');
 	for i := 1 to size do
 	begin
 		read(f,c);
 		AppendChar(buf^,c);
 	end;
 	writeln;
 	close(f);
 	readAudioFile := buf;
 end;
 begin
 	if ParamCount > 0 then
 		filename := ParamStr(1)
 	else
 	begin
 		write('Filename> ');
 		readln(filename);
 	end;
 	err := 1;
 	if ParamCount > 1 then
 		val(ParamStr(2), sampleRate, err);
 	if err > 0 then
 		sampleRate := 32000;
 	buf := readAudioFile(filename);
 	SampleQStart(buf, false, sampleRate);
 	write('Press ESC to stop> ');
 	done := false;
 	while not done do
 	begin
 		read(c);
 		if c = #27 then
 		begin
 			done := true; writeln(';');
 		end
 		else
 		if c = '?' then
 		begin
 			writeln; writeln('Queue: ', SampleQSize);
 		end;
 	end;
 	SampleQStop;
 	dispose(buf);
 end.
--- a/examples/rocket.sprt
+++ b/examples/rocket.sprt
--- a/examples/shinkansen.pict
+++ b/examples/shinkansen.pict
--- a/examples/snow_leopard.pict
+++ b/examples/snow_leopard.pict
--- a/examples/sprite-testcard.sprt
+++ b/examples/sprite-testcard.sprt
--- a/examples/sprites.inc
+++ b/examples/sprites.inc
@ -1,5 +0,0 @@
 type SpritePixels = array[0..128] of integer;
 type BackgroundPixels = array[0..31999] of integer;
 procedure PutSprite(x,y:integer; var sprite: SpritePixels); external;
 procedure UndrawSprite(x,y:integer; var background: BackgroundPixels); external;
--- a/examples/sprites.s
+++ b/examples/sprites.s
@ -1,287 +0,0 @@
 	.EQU SPRITE_HEIGHT 32	; height in lines
 	.EQU SPRITE_STRIPES 4	; width in words i.e. 8-pixel stripes
        .EQU WORDS_PER_LINE 80
        .EQU FB_RA      $900
        .EQU FB_WA      $904
        .EQU FB_IO      $908
        .EQU FB_PS      $90C
 	.EQU FB_PD	$910
 	.EQU FB_CTL	$914
 	.EQU FB_SHIFTER $918
 	.EQU FB_SHIFTCOUNT $91C
 	.EQU FB_SHIFTERM $920
 	.EQU FB_SHIFTERSP $924
 	.EQU FB_MASKGEN $928
 ; calculate vmem address from coordinates
 ; args: x,y
 ; returns: vmem word number
 CALC_VMEM_ADDR:
 	; only works if WORDS_PER_LINE is 80
 	; and pixels per word is 8
 	DUP
 			; y
 	SHL 2
 	SHL 2
 	SHL 2		;   * 64
 	SWAP
 			; + y
 	SHL 2
 	SHL 2		;     * 16
 	ADD
 	SWAP
 			; word offset = X/8
 	SHR
 	SHR
 	SHR
 	ADD
 	RET
 ; put a sprite on screen
 ; arg: x,y pointer to sprite data
 	.EQU PS_VMEM_ADDR	0
 	.EQU PS_SPRITE_DATA	4
 	.EQU PS_SPRITE_LINES	8
 	.EQU PS_X		12
 	.EQU PS_Y		16
 	.EQU PS_SHIFT_C		20
 	.EQU PS_SPILL		24
 	.EQU PS_STRIPE_C	28
 	.EQU PS_BPSAVE		32
 	.EQU PS_FS_ 36
 PUTSPRITE:
 	FPADJ -PS_FS_
 	STORE PS_SPRITE_DATA
 	STORE PS_Y
 	STORE PS_X
 	LOADREG BP
 	STORE PS_BPSAVE
 	LOADC 0
 	STOREREG BP
 	; calculate vmem address
 	LOAD PS_X
 	LOAD PS_Y
 	LOADCP CALC_VMEM_ADDR
 	CALL	
 	STORE PS_VMEM_ADDR
 	LOADC SPRITE_HEIGHT
 	STORE PS_SPRITE_LINES
 	; loop over each line of the sprite
 PS_LOOP1:
 	; set read and write address
 	; in the vga controller
 	LOAD PS_VMEM_ADDR
 	DUP
 	STORE.B FB_RA
 	STORE.B FB_WA
 	LOAD PS_SPRITE_DATA	; address of sprite data
 	DUP
 	INC 4			; increment pointer
 	STORE PS_SPRITE_DATA	; and store it again
 	LOADI			; load word from orig. address
 	; ------- one word of sprite pixels on stack
 	STORE.B FB_SHIFTER
 	LOAD PS_X
 	STORE.B FB_SHIFTCOUNT
 	LOAD.B FB_SHIFTERM	; get shifted mask
 	NOT
 	LOAD.B FB_IO		; and background pixel data
 	AND			; remove foreground pixels
 	LOAD.B FB_SHIFTER	; get shifted pixels
 	OR			; combine with background
 	STORE.B FB_IO		; store into vmem
 	; set counter for remaining stripes
 	LOADC SPRITE_STRIPES - 1
 	STORE PS_STRIPE_C
 	;
 	; process spilled bits and next vertical stripe of sprite data
 	;
 PS_NEXT_STRIPE:
 	;use spill bits from first column
 	LOAD.B FB_SHIFTERSP
 	LOAD PS_SPRITE_DATA	; address of sprite data
 	DUP
 	INC 4			; increment pointer
 	STORE PS_SPRITE_DATA	; and store it again
 	LOADI			; load word from orig. address
 	STORE.B FB_SHIFTER	; store into shifter
 	LOAD PS_X
 	STORE.B FB_SHIFTCOUNT	; shift stuff
 	LOAD.B FB_SHIFTER	; get shifted pixels
 	OR			; combine with spill bits (see above)
 	DUP
 	STORE.B FB_MASKGEN	; store to mask reg to get new mask
 	LOAD.B FB_MASKGEN	; get mask for spill bits + shifted pixels
 	NOT
 	LOAD.B FB_IO		; get vmem data
 	AND			; remove foreground pixels from bg
 	OR			; combine with shifted pixels
 	STORE.B FB_IO		; write to vmem
 	LOAD PS_STRIPE_C	; decrement stripe count
 	DEC 1
 	DUP
 	STORE PS_STRIPE_C
 	CBRANCH.NZ PS_NEXT_STRIPE ; if non-zero, next stripe
 	; write spilled bits of the last stripe into next vmem word
 	LOAD.B FB_SHIFTERSP 	; get spill bits
 	DUP
 	STORE.B FB_MASKGEN
 	LOAD.B FB_MASKGEN	; get sprite mask for spill bits
 	NOT
 	LOAD.B FB_IO		; load next vmem word
 	AND			; apply sprite mask
 	OR			; OR in spill bits
 	STORE.B FB_IO		; write to vmem
 	LOAD PS_SPRITE_LINES	; decrement lines count
 	DEC 1
 	DUP
 	CBRANCH.Z PS_L_XT	; exit if zero
 	STORE PS_SPRITE_LINES
 				; prepare next line
 	LOAD PS_VMEM_ADDR
 	LOADC WORDS_PER_LINE	; increment to next screen line
 	ADD
 	STORE PS_VMEM_ADDR
 	BRANCH PS_LOOP1
 PS_L_XT:
 	DROP
 	LOAD PS_BPSAVE
 	STOREREG BP
 	FPADJ PS_FS_
 	RET
 ; undraw a sprite, i.e. draw background data
 ; over a sprite location
 ; args: x,y, ptr to background data
 	.EQU UD_S_X 0
 	.EQU UD_S_Y 4
 	.EQU UD_S_PXS 8
 	.EQU UD_S_BGDATA 12
 	.EQU UD_S_OFFSET 16
 	.EQU UD_S_BGORIG 20
 	.EQU UD_STRIPE_C 24
 	.EQU UD_S_FS 28
 UNDRAWSPRITE:
 	FPADJ -UD_S_FS
 	STORE UD_S_BGORIG
 	STORE UD_S_Y
 	STORE UD_S_X
 	; calculate pixel shift
 	LOAD UD_S_X
 	LOADC $7
 	AND
 	STORE UD_S_PXS
 	; calculate vmem offset
 	LOAD UD_S_X
 	LOAD UD_S_Y
 	LOADCP CALC_VMEM_ADDR
 	CALL
 	DUP
 	STORE UD_S_OFFSET
 	; calculate background data address from offset
 	SHL 2
 	LOAD UD_S_BGORIG
 	ADD
 	STORE UD_S_BGDATA
 	LOADC SPRITE_HEIGHT	; line count
 UD_S_L1:
 	; store vmem offset into write addr reg
 	LOADCP FB_WA
 	LOAD UD_S_OFFSET
 	STOREI 4	; ugly but fast: reuse addr
 			; with postincrement to
 			; get to FB_IO for STOREI below
 	; load a word of background data
 	LOAD UD_S_BGDATA
 	LOADI
 	; and write it to vmem
 	STOREI
 	; reuse addr from STOREI
 	LOADC SPRITE_STRIPES - 1 ; set remaining stripe count
 	STORE UD_STRIPE_C
 UD_NEXT_STRIPE:
 	; load next word of background data	
 	LOAD UD_S_BGDATA
 	INC 4
 	DUP
 	STORE UD_S_BGDATA
 	LOADI
 	STOREI ; and write it to vmem
 	; reuse addr from STOREI
 	LOAD UD_STRIPE_C	; decrease remaining stripe count
 	DEC 1
 	DUP
 	STORE UD_STRIPE_C
 	CBRANCH.NZ UD_NEXT_STRIPE ; if non-zero, next stripe
 	DROP ; remove addr from STOREI
 	; if pixel shift is zero, no spill word
 	LOAD UD_S_PXS
 	CBRANCH.Z UD_S_L2
 	; load next word of background data
 	LOADCP FB_IO
 	LOAD UD_S_BGDATA
 	INC 4
 	LOADI
 	STOREI ; and write it to vmem
 	DROP
 UD_S_L2:
 	LOAD UD_S_OFFSET
 	LOADCP WORDS_PER_LINE
 	ADD
 	DUP
 	STORE UD_S_OFFSET
 	SHL 2
 	LOAD UD_S_BGORIG
 	ADD
 	STORE UD_S_BGDATA	
 	DEC 1	; decrement counter
 	DUP
 	CBRANCH.NZ UD_S_L1 ; check for zero
 	DROP	; remove counter
 	FPADJ UD_S_FS
 	RET
--- a/examples/sprites.sprt
+++ b/examples/sprites.sprt
--- a/examples/pictviewer.pas
+++ b/examples/pictviewer.pas
@ -1,4 +1,4 @@
-program pictviewer;
+program viewpict;
 type PictData = record
 		magic, mode:integer;
 		palette: array [0..15] of integer;
@ -40,4 +40,5 @@ begin
 	loadPalette(pic);
 	loadPic(pic);
 	read(ch);
 end.
--- a/examples/walking.sprt
+++ b/examples/walking.sprt
--- a/examples/xmas.pas
+++ b/examples/xmas.pas
@ -1,224 +0,0 @@
 (* This program does not work anymore, because
   it uses the old sprite routines with 16x16 sprites.
   It is only included for historical reasons.
   *)
 program XmasAnimation;
 uses sprites;
 type PictData = record
 		magic, mode:integer;
 		palette: array [0..15] of integer;
 		pixeldata: array [0..31999] of integer;
 	end;
     Sprite = record
     		x,y:integer;
     		oldX,oldY:integer;
     		xdelta,ydelta:integer;
 		curFrame:integer;
 		frameCount:integer;
 		frameTime:integer;
 		frameLeft:integer;
 		changed:boolean;
 		frame:array [0..3] of SpritePixels;
 	end;
 var pic:PictData;
    filename:string;
    infile:file;
    ch:char;
    santaSprite: Sprite;
    deerSprite: Sprite;
    ohDeerSprite: Sprite;
    rudolfSprite: Sprite;
    smokeSprite: Sprite;
 procedure WaitVSync; external;
 procedure loadPalette(var pic:PictData);
 var i:integer;
 begin
 	for i := 0 to 15 do
 		setpalette(i, pic.palette[i]);
 end;
 procedure showPic(var pic:PictData);
 begin
 	PutScreen(pic.pixeldata);
 end;
 procedure loadSpriteFrame(var aSprite:Sprite;spriteIndex:integer;
 		var sheetFile:file;sheetIndex:integer);
 begin
 	seek(sheetFile, 8 + sheetIndex * 128);
 	read(sheetFile, aSprite.frame[spriteIndex]);
 	if aSprite.frameCount <= spriteIndex then
 		aSprite.frameCount := spriteIndex + 1;
 	aSprite.curFrame := 0;
 	writeln('loaded sprite frame ', spriteIndex, ' from ', sheetIndex);
 end;
 procedure animateSprite(var aSprite:Sprite);
 var frameIndex:integer;
    frameTime,frameLeft:integer;
    ydelta:integer;
    oldX,oldY:integer;
 begin
 	ydelta := aSprite.ydelta;
 	frameIndex := aSprite.curFrame;
 	frameTime := aSprite.frameTime;
 	frameLeft := aSprite.frameLeft;
 	oldX := aSprite.x; oldY := aSprite.y;
 	aSprite.oldX := oldX; aSprite.oldY := oldY;
 	frameLeft := frameLeft - 1;
 	if frameLeft <= 0 then
 	begin
 		frameIndex := frameIndex + 1;
 		frameLeft := aSprite.frameTime;
 		aSprite.frameLeft := frameLeft;
 		aSprite.curFrame := frameIndex;
 		if frameIndex >= aSprite.frameCount
 		then
 			aSprite.curFrame := 0;
 		if frameIndex = 1 then
 		begin
 			ydelta := - ydelta;
 			aSprite.ydelta := ydelta;
 		end;
 		aSprite.y := aSprite.y + ydelta;
 	end;
 	aSprite.frameLeft := frameLeft;
 	aSprite.x := aSprite.x + aSprite.xdelta;
 	if aSprite.x > 620 then aSprite.x := 0;	
 end;
 procedure animate;
 var i:integer;
    ydelta:integer;
    frameIndex:integer;
    frameTime:integer;
    oldX,oldY:integer;
 begin
 	santaSprite.x := 0;
 	santaSprite.y := 60;
 	santaSprite.frameTime := 10;
 	santaSprite.xdelta := 2;
 	santaSprite.ydelta := 1;
 	smokeSprite.x := 434;
 	smokeSprite.y := 252;
 	smokeSprite.frameTime := 20;
 	deerSprite.x := 18;
 	deerSprite.y := 60;
 	deerSprite.frameTime := 10;
 	deerSprite.xdelta := 2;
 	deerSprite.ydelta := 1;
 	ohDeerSprite.x := 33;
 	ohDeerSprite.y := 61;
 	ohDeerSprite.frameTime := 10;
 	ohDeerSprite.xdelta := 2;
 	ohDeerSprite.ydelta := 1;
 	rudolfSprite.x := 49;
 	rudolfSprite.y := 60;
 	rudolfSprite.frameTime := 10;
 	rudolfSprite.xdelta := 2;
 	rudolfSprite.ydelta := 1;
 	ydelta := 1;
 	frameTime := santaSprite.frameTime;
 	while not ConAvail do
 	begin
 		frameIndex := santaSprite.curFrame;
 		oldX := santaSprite.x; oldY := santaSprite.y;
 		PutSprite(oldX, oldY, santaSprite.frame[frameIndex]);
 		i := i + 1;
 		frameTime := frameTime - 1;
 		if frameTime = 0 then
 		begin
 			frameTime := santaSprite.frameTime;
 			santaSprite.curFrame := frameIndex + 1;
 			if frameIndex >= santaSprite.frameCount
 			then
 				santaSprite.curFrame := 0;
 			if frameIndex = 0 then ydelta := - ydelta;
 			santaSprite.y := santaSprite.y + ydelta;
 		end;
 		santaSprite.x := santaSprite.x + 2;
 		if santaSprite.x > 620 then santaSprite.x := 0;
 		PutSprite(deerSprite.x, deerSprite.y,
 			deerSprite.frame[deerSprite.curFrame]);
 		PutSprite(ohDeerSprite.x, ohDeerSprite.y,
 			ohDeerSprite.frame[ohDeerSprite.curFrame]);
 		PutSprite(rudolfSprite.x, rudolfSprite.y,
 			rudolfSprite.frame[rudolfSprite.curFrame]);
 		PutSprite(smokeSprite.x, smokeSprite.y,
 			smokeSprite.frame[smokeSprite.curFrame]);
 		animateSprite(deerSprite);
 		animateSprite(ohDeerSprite);
 		animateSprite(rudolfSprite);
 		animateSprite(smokeSprite);
 		Delay(10);
 		WaitVSync;
 		UndrawSprite(oldX, oldY, pic.pixeldata);
 		UndrawSprite(deerSprite.oldX, deerSprite.oldY, pic.pixeldata);
 		UndrawSprite(ohDeerSprite.oldX, ohDeerSprite.oldY, pic.pixeldata);
 		UndrawSprite(rudolfSprite.oldX, rudolfSprite.oldY, pic.pixeldata);
 		UndrawSprite(smokeSprite.oldX, smokeSprite.oldY, pic.pixeldata);
 	end;
 end;
 begin
 	filename := 'background.pict';
 	open(infile, filename, ModeReadonly);
 	read(infile, pic);
 	close(infile);
 	writeln('magic: ', pic.magic, ' mode:', pic.mode);
 	loadPalette(pic);
 	showPic(pic);
 	open(infile, 'sprites.sprt', ModeReadOnly);
 	loadSpriteFrame(santaSprite, 0, infile, 0);
 	loadSpriteFrame(santaSprite, 1, infile, 1);
 	loadSpriteFrame(deerSprite, 0, infile, 5);
 	loadSpriteFrame(deerSprite, 1, infile, 6);
 	loadSpriteFrame(deerSprite, 2, infile, 7);
 	loadSpriteFrame(ohDeerSprite, 0, infile, 7);
 	loadSpriteFrame(ohDeerSprite, 1, infile, 5);
 	loadSpriteFrame(ohDeerSprite, 2, infile, 6);
 	loadSpriteFrame(rudolfSprite, 0, infile, 3);
 	loadSpriteFrame(rudolfSprite, 1, infile, 4);
 	loadSpriteFrame(rudolfSprite, 2, infile, 2);
 	loadSpriteFrame(smokeSprite, 0, infile, 8);
 	loadSpriteFrame(smokeSprite, 1, infile, 9);
 	loadSpriteFrame(smokeSprite, 2, infile, 10);
 	loadSpriteFrame(smokeSprite, 3, infile, 11);
 	close(infile);
 	animate;
 end.
--- a/examples/xmas25.pas
+++ b/examples/xmas25.pas
@ -1,251 +0,0 @@
 {$H2560}
 {$S8}
 program xmas252;
 uses pcmaudio, fastfire, tiles;
 const MAXX = FIREWIDTH;
      MAXY = FIREHEIGHT;
 (* type PixelData = array[0..31999] of integer; *)
 type Picture = record
 		magic:integer;
 		mode:integer;
 		palette: array[0..15] of integer;
 		pixels: PixelData;
 	end;
 var firecells: FireBuf;
    firepalette: array [0..15] of integer =
    	{ ( $FFA, $FF8, $FF4, $FF0, $FE0, $FD0, $FA0, $F90,
    	  $F00, $E00, $D00, $A00, $800, $600, $300, $000); }
    	{ ( $FFA, $FFA, $FFA, $FFA, $FF0, $FF0, $FF0, $FF0, }
    	  ( $00F, $00F, $00F, $00F, $00F, $00F, $00F, $00F,
    	  $FF0, $FD0, $FA0, $C00, $A00, $700, $400, $000);
    x,y:integer;
    infile:file;
    pic:^Picture;
    tilesheet:^Picture;
    animationTick:integer;
    animationHold:integer;
    animationState:integer;
    filename: string;
    audiodata: SndBufPtr;
 procedure createPalette;
 var i:integer;
 begin
 	for i := 15 downto 0 do
 		setpalette(15 - i, firepalette[i]);
 end;
 procedure fireItUp;
 var x,y:integer;
 begin
 	y := MAXY - 1;
 	for x := 1 to MAXX - 1 do
 		firecells[y, x] := random and 127;
 end;
 procedure updateFire;
 var i,x,y:integer;
 begin
 	for y := 0 to MAXY - 2 do
 		for x := 1 to MAXX - 1 do
 		begin
 			i :=
 				((firecells[y + 1, x - 1]
 				+ firecells[y + 1, x]
 				+ firecells[y + 1, x + 1]
 				+ firecells[y + 2, x])
 				) shr 2;
 			if i > 0 then
 				i := i - 1;
 			firecells[y, x] := i;
 		end;
 end;
 procedure drawFire(startX,startY:integer);
 var x, y, col, col2:integer;
 begin
 	for y := 0 to MAXY - 1 do
 	begin
 		x := 0;
 		for col in firecells[y] do
 		begin
 			{ scale and clamp color value }
 			col2 := col shr 3;
 			if col2 > FIREMAXCOLOR then col2 := FIREMAXCOLOR;
 			putpixel(startX + x, startY + y, col2);
 			x := x + 1;
 		end;
 	end;
 end;
 procedure readBackgroundPic(filename:string);
 var i:integer;
 begin
 	open(infile, filename, ModeReadonly);
 	read(infile, pic^);
 	close(infile);
 	for i := 0 to 15 do
 		SetPalette(i, pic^.palette[i]);
 	PutScreen(pic^.pixels);
 end;
 procedure animate;
 var tileSrcX,tilesrcY:integer;
 begin
 	animationTick := animationTick + 1;
 	if animationHold = 0 then
 		animationHold := 40;
 	if animationTick < animationHold then
 		exit;
 	animationTick := 0;
 	case animationState of
 	0: begin
 		tileSrcX := 0;
 		tileSrcY := 0;
 		animationHold := 40;
 	   end;
 	1: begin
 		tileSrcX := 19;
 		tileSrcY := 0;
 		animationHold := 20;
 		if random and 7 > 4 then
 			animationState := -1;
 	   end;
 	2: begin
 		tileSrcX := 38;
 		tileSrcY := 0;
 		animationHold := 2;
 	   end;
 	3: begin;
 		tileSrcX := 57;
 		tileSrcY := 0;
 		animationHold := 2;
 	   end;
 	4: begin
 		tileSrcX := 0;
 		tileSrcY := 13;
 		animationHold := 15;
 	   end;
 	5: begin
 		tileSrcX := 57;
 		tileSrcY := 0;
 		animationHold := 2;
 	   end;
 	6: begin
 		tileSrcX := 38;
 		tileSrcY := 0;
 		animationHold := 2;
 	   end;
 	7: begin
 		tileSrcX := 0;
 		tileSrcY := 0;
 		animationHold := 2;
 		animationState := -1;
 	   end;
 	end;
 	CopyTilesScr(tilesheet^.pixels,
 		tileSrcX, tileSrcY,
 		34,34,
 		19,13);
 	animationState := animationState + 1;
 end;
 procedure readTilesheet;
 var filename:string;
    i:integer;
 begin
 	filename := 'tilesheet.pict';
 	open(infile, filename, ModeReadonly);
 	read(infile, tilesheet^);
 	close(infile);
 end;
 function newAudioData(fname:string):SndBufPtr;
 var i,size:integer;
    c:char;
    buf:SndBufPtr;
    f:file;
 begin
 	open(f, fname, ModeReadOnly);
 	size := FileSize(f);
 	new(buf, size);
 	buf^ := '';
 	write('Reading ', size, ' bytes...');
 	for i := 1 to size do
 	begin
 		read(f,c);
 		AppendChar(buf^,c);
 	end;
 	writeln;
 	close(f);
 	newAudioData := buf;
 end;
 begin
 	if ParamCount > 0 then
 		filename := ParamStr(1)
 	else
 		filename := 'xmas25bg.pict';
 	Randomize;
 	audiodata := newAudioData('fireplace-loop.tdrau');
 	InitGraphics;
 	new(pic);
 	readBackgroundPic(filename);
 	new(tilesheet);
 	readTilesheet;
 	SampleQStart(audiodata, true, 22050);
 	while not ConAvail do
 	begin
 		fireItUp;
 		FastFireUpdate(firecells);
 		{ updateFire; }
 		FastFireDraw(firecells, 216, 165);
 		{ drawFire(216, 165); }
 		animate;
 	end;
 	SampleQStop;
 	for y := 0 to MAXY do
 	begin
 		x := firecells[y, 10];
 		drawline(0, y, x, y, 1);
 	end;
 	InitGraphics;
 	dispose(tilesheet);
 	dispose(pic);
 	dispose(audiodata);
 end.
--- a/lib/corelib.s
+++ b/lib/corelib.s
@ -588,19 +588,13 @@ DIVU_END:
 ; wait approx. 1 millisecond
 ;
-; the ROM at address 4
+; 83.333 MHz Clock, three instructions a 4 cycles
-; contains the cpu clock freq in KHz
+; 83333 / 12 = 6944.4166
-	.EQU CLK_KHZ_ADDR 4
+; works only if executed without wait states (i.e.
 ; from BRAM/SRAM)
 WAIT1MSEC:
-	LOADC CLK_KHZ_ADDR
+	LOADCP 6944
 	LOADI
 	; divide by 16
 	SHR
 	SHR
 	SHR
 	SHR
 WAIT1LOOP:
 	INC 0 ; NOP to make the loop 16 cycles long
 	DEC 1
 	DUP
 	CBRANCH.NZ WAIT1LOOP
@ -612,9 +606,6 @@ WAIT1LOOP:
 ; length must be multiple of wordsize.
 ; if it is not, the last (partial) word is not cleared.
 _CLEARMEM:
 	OVER	; check for null pointer
 	CBRANCH.Z CLEARMEM_X
 	SHR
 	SHR	; calculate length in words
@ -701,37 +692,113 @@ CMPWORDS_XT2:
 ; --------- Graphics Library ---------------
 	; vga controller registers
 	.EQU FB_RA	$900
-	.EQU FB_WA	$904
+	.EQU FB_WA	$901
-	.EQU FB_IO	$908
+	.EQU FB_IO	$902
-	.EQU FB_PS	$90C
+	.EQU FB_PS	$903
-	.EQU FB_PD	$910
+	.EQU FB_PD	$904
-	.EQU FB_CTL	$914
+	.EQU FB_CTL	$905
-	.EQU FB_SHIFTER $918
+; set a pixel in fb memory
-	.EQU FB_SHIFTCOUNT $91C
+; parameters: x,y - coordinates
-	.EQU FB_SHIFTERM $920
+PUTPIXEL_1BPP:
-	.EQU FB_SHIFTERSP $924
+	; calculate vmem address:
-	.EQU FB_MASKGEN $928
+	OVER ; duplicate x
 	; divide x by 32
 	SHR
 	SHR
 	SHR
 	SHR
 	SHR
 	SWAP
 	; multiply y by words per line
 	SHL 2
 	SHL 2
 	SHL
-; draw a single pixel
+	ADD ; add results together for vmem addr
 ; args: x, y, color
 	DUP
 	LOADCP FB_WA
 	SWAP
 	STOREI	; store to framebuffer write addr register
 	DROP
 	LOADCP FB_RA ; and to framebuffer read addr register
 	SWAP
 	STOREI
 	DROP
 	; x is now at top of stack
 	; get bit value from x modulo 32
 	LOADC 31
 	AND
 	SHL 2 ; (x & 31) * 4 = offset into table
 	LOADCP INT_TO_PIX_TABLE
 	ADD
 	LOADI
 	LOADCP FB_IO
 	; read old vmem value
 	LOADCP FB_IO
 	LOADI
 	; or in new bit
 	OR
 	; write new value
 	STOREI
 	DROP
 	RET
 INT_TO_PIX_TABLE:
 	.WORD %10000000_00000000_00000000_00000000
 	.WORD %01000000_00000000_00000000_00000000
 	.WORD %00100000_00000000_00000000_00000000
 	.WORD %00010000_00000000_00000000_00000000
 	.WORD %00001000_00000000_00000000_00000000
 	.WORD %00000100_00000000_00000000_00000000
 	.WORD %00000010_00000000_00000000_00000000
 	.WORD %00000001_00000000_00000000_00000000
 	.WORD %00000000_10000000_00000000_00000000
 	.WORD %00000000_01000000_00000000_00000000
 	.WORD %00000000_00100000_00000000_00000000
 	.WORD %00000000_00010000_00000000_00000000
 	.WORD %00000000_00001000_00000000_00000000
 	.WORD %00000000_00000100_00000000_00000000
 	.WORD %00000000_00000010_00000000_00000000
 	.WORD %00000000_00000001_00000000_00000000
 	.WORD %00000000_00000000_10000000_00000000
 	.WORD %00000000_00000000_01000000_00000000
 	.WORD %00000000_00000000_00100000_00000000
 	.WORD %00000000_00000000_00010000_00000000
 	.WORD %00000000_00000000_00001000_00000000
 	.WORD %00000000_00000000_00000100_00000000
 	.WORD %00000000_00000000_00000010_00000000
 	.WORD %00000000_00000000_00000001_00000000
 	.WORD %00000000_00000000_00000000_10000000
 	.WORD %00000000_00000000_00000000_01000000
 	.WORD %00000000_00000000_00000000_00100000
 	.WORD %00000000_00000000_00000000_00010000
 	.WORD %00000000_00000000_00000000_00001000
 	.WORD %00000000_00000000_00000000_00000100
 	.WORD %00000000_00000000_00000000_00000010
 	.WORD %00000000_00000000_00000000_00000001
 PUTMPIXEL:
 	LOADC 1
 ; set a pixel in fb memory
 ; parameters: x,y,color - coordinates, color value (0-15)
 PUTPIXEL:
 PUTPIXEL_4BPP:
 	.EQU PUTPIXEL_X 0
 	.EQU PUTPIXEL_Y 4
 	.EQU PUTPIXEL_COLOR 8
-	.EQU PUTPIXEL_BPSAV 12
+	.EQU PUTPIXEL_PIXPOS 12
 	.EQU PUTPIXEL_FS 16
 	FPADJ -PUTPIXEL_FS
 	STORE PUTPIXEL_COLOR
 	STORE PUTPIXEL_Y
 	STORE PUTPIXEL_X
 	LOADREG BP
 	STORE PUTPIXEL_BPSAV
 	LOADC 0
 	STOREREG BP
 	; calculate vmem address: (x / 8) + (y * 80)
 	LOAD PUTPIXEL_X
@ -746,60 +813,86 @@ PUTPIXEL_4BPP:
 	SHL 2 ; * 16
 	DUP
 	SHL 2; * 64
-	ADD  ; y*16 + y*64
+	ADD  ; x*16 + x*64
 	ADD ; add results together for vmem addr
-	DUP
+	LOADCP FB_WA
-	STORE.B FB_WA	; set as write and read addresses
+	OVER
-	STORE.B FB_RA
+	STOREI	; store to framebuffer write addr register
 	DROP
 	LOADCP FB_RA ; and to framebuffer read addr register
 	SWAP	; swap addr and value for STOREI
 	STOREI
 	DROP
 	LOAD PUTPIXEL_X
 	;		|0000.0000|0000.0000|0000.0000|0000.1111|
 	LOADC 7
 	AND		; calculate pixel position in word
 	LOADC 7
 	SWAP
 	SUB		; pixpos = 7 - (x & 7)
 	STORE PUTPIXEL_PIXPOS
 	LOAD PUTPIXEL_COLOR
-	CBRANCH.Z PUTPX_CLR	; color 0 is special case
+	LOAD PUTPIXEL_PIXPOS
-
+	SHR		; rcount = pixpos / 2
-	; create pixel data from color value in
+ROTLOOP_:
-	; leftmost pixel data bits (31-28)
+	DUP		; exit loop if rcount is 0
-	LOADC 0
+	CBRANCH.Z ROTLOOP_END
-	LOAD PUTPIXEL_COLOR
+	SWAP		; pixel value is now on top of stack
-	BPLC
+	BROT		; value = value << 8
 	SWAP		; rcount is now on top of stack
 	DEC 1		; rcount = rcount - 1
 	BRANCH ROTLOOP_
 ROTLOOP_END:
 	DROP		; drop rcount
 	; shifted pixel value is now at top of stack
 	LOAD PUTPIXEL_PIXPOS
 	LOADC 1
 	AND
 	CBRANCH.Z EVEN_PIXPOS
 	SHL 2	; if pixpos is odd, shift by 4 bits
 	SHL 2
-	SHL 2
+EVEN_PIXPOS:
-	STORE.B FB_SHIFTER	; store pixel into shifter
+	LOAD PUTPIXEL_X
 	; get bit value from x modulo 8
 	LOADC 7
 	AND
 	SHL 2 ; (x & 7) * 4 = offset into table
 	LOADCP INT_TO_MASK_TABLE
 	ADD
 	LOADI
-	LOAD PUTPIXEL_X 	; use x coord as shift count
+	; read old vmem value
-	STORE.B FB_SHIFTCOUNT	; writing triggers shifting
+	LOADCP FB_IO
 	LOADI
 	; mask bits
 	AND
 	; or in shifted pixel value
 	OR
-	LOAD.B FB_SHIFTERM	; get shift result as mask
+	; write new value
-	NOT			; invert to get background mask
+	LOADCP FB_IO
-	LOAD.B FB_IO		; get background pixel data
+	SWAP
-	AND			; remove bits for new pixel from bg
+	STOREI
-
+	DROP
 	LOAD.B FB_SHIFTER	; load shifted pixel
 	OR			; OR in new pixel bits
 	STORE.B FB_IO		; write new pixel data word to vmem
 PUTPX_XT:
 	LOAD PUTPIXEL_BPSAV
 	STOREREG BP
 	FPADJ PUTPIXEL_FS
 	RET
-PUTPX_CLR:
+	.CPOOL
 	LOADCP $F0000000	; mask for leftmost pixel
 	STORE.B FB_SHIFTER	; shift accordingly
 	LOAD PUTPIXEL_X
 	STORE.B FB_SHIFTCOUNT
 	LOAD.B FB_SHIFTER	; get shifted value
 	NOT			; invert for real mask
 	LOAD.B FB_IO		; get background pixels
 	AND			; clear pixel with mask
 	STORE.B FB_IO		; no need to OR in new pixel, just store to vmem
 	BRANCH PUTPX_XT
 INT_TO_MASK_TABLE:
 	.WORD %00001111_11111111_11111111_11111111
 	.WORD %11110000_11111111_11111111_11111111
 	.WORD %11111111_00001111_11111111_11111111
 	.WORD %11111111_11110000_11111111_11111111
 	.WORD %11111111_11111111_00001111_11111111
 	.WORD %11111111_11111111_11110000_11111111
 	.WORD %11111111_11111111_11111111_00001111
 	.WORD %11111111_11111111_11111111_11110000
 ; draw a line between two points
 ; parameters: x0, y0, x1, y1, color
@ -977,7 +1070,7 @@ SETPALETTE:
 DEFAULT_PALETTE:
 	.WORD 0,    $FFF, $F00, $0F0, $00F, $0FF, $F0F, $FF0
-	.WORD $777, $AAA, $700, $070, $007, $077, $707, $770
+	.WORD $777, $777, $700, $070, $007, $077, $707, $770
 ; set whole video memory to zero
 CLEARGRAPHICS:
--- a/lib/pcmaudio.inc
+++ b/lib/pcmaudio.inc
@ -1,7 +0,0 @@
 type SndBuf = string[32768];
 type SndBufPtr = ^SndBuf;
 procedure PlaySample(buf:SndBufPtr;sampleRate:integer); external;
 procedure SampleQStart(buf:SndBufPtr;loop:boolean;sampleRate:integer); external;
 procedure SampleQStop; external;
 function SampleQSize:integer; external;
--- a/lib/pcmaudio.s
+++ b/lib/pcmaudio.s
@ -1,304 +0,0 @@
 	.EQU AUDIO_BASE $A00
 	.EQU IRQC_REG $980
 	.EQU IRQC_EN $80
 	.EQU CPU_FREQ 77000000
 ; args: sample rate
 START_PCMAUDIO:
 	; calculate clock divider
 	LOADCP CPU_FREQ
 	SWAP
 	LOADCP _DIV
 	CALL
 	LOADC AUDIO_BASE + 4
 	SWAP		; put clock divider on ToS
 	STOREI 4
 	LOADCP 32768	; set amplitude to biased 0
 	STOREI
 	DROP
 	LOADC AUDIO_BASE
 	LOADC 1	; enable channel
 	STOREI
 	DROP
 	RET
 STOP_AUDIO:
 	LOADC AUDIO_BASE
 	LOADC 0
 	STOREI
 	DROP
 	RET
 ; args: pointer to pascal string, sample rate
 	.EQU PS_PTR 0
 	.EQU PS_COUNT 4
 	.EQU PS_FS 12
 PLAYSAMPLE:
 	FPADJ -PS_FS
 	LOADCP START_PCMAUDIO
 	CALL
 	DUP
 	LOADI		; get string size from header
 	SHR		; divide by 4 to get word count
 	SHR
 	STORE PS_COUNT
 	INC 8		; skip rest of header
 	STORE PS_PTR	; store sample data pointer
 PS_L0:
 	LOAD PS_PTR	; load pointer
 	INC.S1.X2Y 4	; increment and keep old value
 	STORE PS_PTR	; store incremented value
 	LOADI		; load 32 bit word
 	DUP
 	BROT		; get upper 16 bit word
 	BROT
 	LOADCP $FFFF
 	AND
 	LOADCP PLAY_1SAMPLE
 	CALL
 	LOADCP $FFFF	; get lower 16 bit word
 	AND
 	LOADCP PLAY_1SAMPLE
 	CALL
 	LOAD PS_COUNT	; load word count
 	DEC 1		; decrement
 	DUP
 	STORE PS_COUNT
 	CBRANCH.NZ PS_L0 ; loop if not zero
 	LOADCP STOP_AUDIO
 	CALL
 	FPADJ PS_FS
 	RET
 ; play one sample, waiting
 ; for the clock divider, which
 ; is visible via the phase flag
 ; args: 16-bit unsigned sample
 PLAY_1SAMPLE:
 PLAY1_L0:
 	LOADC AUDIO_BASE
 	LOADI
 	LOADC 8		; get fifo_full flag
 	AND
 	CBRANCH.NZ PLAY1_L0 ; loop if fifo is full
 	LOADC AUDIO_BASE+8 ; store amplitude value
 	SWAP
 	STOREI
 	DROP
 	RET
 ; set sample queue count and pointer from string header
 ; args: pointer to string/SndBufPtr
 _STR2SMPLQPTR:
 	LOADCP SMPLQ_COUNT
 	OVER
 	LOADI		; get string size from header
 	SHR		; divide by 4 to get word count
 	SHR
 	STOREI
 	DROP
 	LOADCP SMPLQ_PTR
 	SWAP
 	INC 8		; skip rest of header
 	STOREI		; store sample data pointer
 	DROP
 	RET
 ; start interrupt-driven sample playback
 ; args: pointer to pascal string, loop flag, sample rate
 SAMPLEQSTART:
 	LOADCP START_PCMAUDIO ; sample rate is on ToS as arg to subroutine
 	CALL
 	SWAP		; swap loop flag and buf ptr
 	LOADCP _STR2SMPLQPTR
 	CALL
 	; loop flag is now on ToS
 	CBRANCH.Z SQ_S_1
 	; if nonzero, set loop ptr
 	LOADCP SMPLQ_PTR
 	LOADI
 	DEC 8	; subtract offset for string header again
 	BRANCH SQ_S_0
 SQ_S_1:
 	LOADC 0
 SQ_S_0:
 	LOADCP SMPLQ_NEXT
 	SWAP
 	STOREI
 	DROP	
 	LOADC AUDIO_BASE
 	LOADC 17	; enable channel, enable interrupt
 	STOREI
 	DROP
 	LOADCP SMPLQ_ISR ; set interrupt handler
 	STOREREG IV
 	LOADC IRQC_REG	; enable irq
 	LOADC IRQC_EN
 	STOREI
 	DROP
 	RET
 SAMPLEQSTOP:
 	LOADCP SMPLQ_PTR
 	LOADC 0
 	STOREI
 	DROP
 	LOADCP STOP_AUDIO
 	CALL
 	LOADC IRQC_REG	; disable irq
 	LOADC 0
 	STOREI
 	DROP
 	RET
 SAMPLEQSIZE:
 	LOADCP SMPLQ_COUNT
 	LOADI
 	RET
 SMPLQ_PTR: .WORD 0
 SMPLQ_COUNT: .WORD 0
 SMPLQ_NEXT: .WORD 0
 SMPLQ_ISR:
 	LOADC IRQC_REG
 	LOADI
 	LOADC 4	; check for audio interrupt
 	AND
 	CBRANCH.Z SMPLQ_I_XT ; if flag not set, exit
 SMPLQ_I_L:
 	LOADCP SMPLQ_PTR
 	LOADI			; load word pointer
 	DUP
 	CBRANCH.NZ SMPLQ_I_B	; check for null pointer
 	DROP
 	BRANCH SMPLQ_I_XT	; if null, end interrupt routine
 SMPLQ_I_B:
 	LOADI	; load next word which contains two samples
 	DUP
 	BROT	; get high half-word
 	BROT
 	LOADCP $FFFF
 	AND
 	LOADC AUDIO_BASE+8
 	SWAP
 	STOREI	; write sample, keep addr
 	SWAP	; addr to NoS, lower halfword on ToS
 	LOADCP $FFFF
 	AND
 	STOREI	; write sample
 	DROP
 	; decrement word count
 	LOADCP SMPLQ_COUNT
 	LOADI.S1.X2Y		; load counter, keep addr
 	DEC 1
 	DUP
 	CBRANCH.Z SMPLQ_I_END	; end if zero
 	STOREI			; store new counter value
 	DROP
 	; increment pointer
 	LOADCP SMPLQ_PTR
 	LOADI.S1.X2Y
 	INC 4
 	STOREI
 	DROP
 	; put up to 16 samples into the sample queue
 	LOADCP SMPLQ_COUNT
 	LOADI	; load word counter again
 	LOADC 7 ; check if count modulo 7 = 0
 	AND
 	CBRANCH.NZ SMPLQ_I_L ; if not, next two samples
 	; check if fifo is full
 	; does not work reliably when running in DRAM,
 	; maybe because at least one sample has already played
 	; since start of ISR?
 ;	LOADC AUDIO_BASE
 ;	LOADI
 ;	LOADC 8	; fifo_full
 ;	AND
 ;	CBRANCH.Z SMPLQ_I_L ; next sample if not full
 	BRANCH SMPLQ_I_XT
 	; end of sample buffer, check for next
 SMPLQ_I_END:
 	DROP
 	DROP
 	LOADCP SMPLQ_NEXT	; skip to end
 	LOADI			; if NEXT ptr is zero
 	DUP
 	CBRANCH.Z SMPLQ_I_END1
 	LOADCP _STR2SMPLQPTR
 	CALL
 	BRANCH SMPLQ_I_XT
 	; end playback, set ptr and counter to zero
 SMPLQ_I_END1:
 	DROP
 	LOADCP SMPLQ_PTR
 	LOADC 0
 	STOREI
 	DROP
 	LOADCP SMPLQ_COUNT
 	LOADC 0
 	STOREI
 	DROP
 	; set amplitude out to zero (biased)
 	LOADC AUDIO_BASE+8
 	LOADCP 32768
 	STOREI
 	DROP
 	; exit without enabling interrupts for this channel
 	BRANCH SMPLQ_I_XT2
 SMPLQ_I_XT:
 	LOADC AUDIO_BASE
 	LOADC 17	; re-enable channel interrupt
 	STOREI
 	DROP
 SMPLQ_I_XT2:
 	LOADC IRQC_REG		; re-enable interrupts
 	LOADC IRQC_EN
 	STOREI
 	DROP
 	LOADREG IR		; jump via interrupt return register
 	JUMP
--- a/lib/rommon.s
+++ b/lib/rommon.s
@ -7,16 +7,8 @@
 	.EQU UART_REG 2048
 	.EQU MON_ADDR 64512
 	.EQU CLK_KHZ 76923
 	BRANCH 2	; the very first instruction is not
 			; executed correctly
 	BRANCH MON_START ; branch over constant
 CLK_KHZ_ADDR:
 	.WORD CLK_KHZ  ; to calibrate the delay loop
 MON_START:
 	LOADCP 65020 ; initialise FP and RP registers
 	STOREREG FP
 	LOADCP 65024
@ -790,17 +782,13 @@ COPY_BLK1:
 ; wait approx. 1 millisecond
 ;
 ; 83.333 MHz Clock, three instructions a 4 cycles
 ; 83333 / 12 = 6944.4166
 ; works only if executed without wait states (i.e.
 ; from BRAM/SRAM)
 WAIT1MSEC:
-	; get clock freq in khz
+	LOADCP 6944
 	LOADC CLK_KHZ_ADDR
 	LOADI
 	; divide by 16
 	SHR
 	SHR
 	SHR
 	SHR
 WAIT1LOOP:
 	INC 0	; NOP to make loop 16 cycles long
 	DEC 1
 	DUP
 	CBRANCH.NZ WAIT1LOOP
@ -810,7 +798,7 @@ WAIT1LOOP:
 %include "sdcardboot.s"
 	.CPOOL
 MESSAGE:
-	.BYTE 13,10,"ROM Monitor v3.1.0", 13, 10,
+	.BYTE 13,10,"ROM Monitor v3.0.3", 13, 10,
 	      "Set A)ddress   D)eposit   eX)amine   L)oad   G)o  B)oot",13,10,0
 PROMPT2:
 	.BYTE "]> ",0
--- a/lib/runtime.s
+++ b/lib/runtime.s
@ -1616,7 +1616,7 @@ MEM_FREE_XT:
 ; Since the return stack is no longer valid afterwards, directly
 ; jumps to _MAIN instead of using RET.
-; parameters: [ start of heap address ]
+; parameters: [ _MAIN entry point, start of heap address ]
 _MEM_INIT:
 	; initialize anchor chunk with start of heap address
 	; and heap size - header size
@ -1764,34 +1764,6 @@ MEM_DUMP_L0:
 	DROP
 	RET
 ; calculate total free heap space
 ; args: none
 ; returns: cumulative size of all free chunks in bytes
 MEMAVAIL:
 	FPADJ -4
 	LOADC 0
 	STORE 0	; start with zero as result
 	LOADCP _HEAP_ANCHOR
 MAV_L:
 	DUP	; dup chunk ptr for later
 	INC 4	; move to size field
 	LOADI	; load chunk size
 	LOAD 0  ; add to current result value
 	ADD
 	STORE 0
 	LOADI	; load next ptr
 	DUP
 	LOADCP _HEAP_ANCHOR ; compare with anchor
 	CMPU NE
 	CBRANCH MAV_L       ; if not equal, loop
 MAX_XT:
 	DROP	; drop chunk ptr
 	LOAD 0	; put result value on stack
 	FPADJ 4
 	RET
 ; check if a pointer is part of the free list
 ; args: pointer returned by MEM_ALLOC
 ; throws runtime error if the pointer is found
@ -1931,12 +1903,6 @@ _CLEARESTACK_XT:
 ; Terminate program: clear estack and
 ; jump to coreloader
 PTERM:
 	; just to be safe, disable interrupts
 	LOADC $980
 	LOADC 0
 	STOREI
 	DROP
 	LOADCP _CLEARESTACK
 	CALL
 	LOADCP LOADER_START
--- a/lib/sdcardlib.s
+++ b/lib/sdcardlib.s
@ -264,8 +264,8 @@ CARD_OK:
 ; set fast transfer rate
 CARDFASTCLK:
 	LOADC SPIREG
-	; set clock divider to ~2.75MHz
+	; set clock divider to ~2,6MHz
-	LOADCP SPI_CLK_DIV_WR,7 ; using the LOADCP with offset syntax here
+	LOADCP SPI_CLK_DIV_WR,10 ; using the LOADCP with offset syntax here
 	STOREI
 	DROP
 	RET
--- a/lib/stdlib.inc
+++ b/lib/stdlib.inc
@ -18,9 +18,8 @@ const IONoError 	=  0;
      IOReadOnly 	=  8;
      IOInvalidOp	=  9;
      IOInvalidFormat   = 10;
-      IONoMem		= 11;
+      IOUserIntr	= 11;
-      IOUserIntr	= 12;
+      IOMaxErr          = 11;
      IOMaxErr          = 12;
 const PArgMax = 7;
@ -149,11 +148,10 @@ procedure appendchar(var s:string; aChar:char); external;
 procedure strmoveup(var s:string;index,length,delta:integer); external;
 procedure strmovedown(var s:string;index,length,delta:integer); external;
 procedure RuntimeError(var s:string); external;
 function MemAvail:integer; external;
 (* from stdlib *)
-function copy(s:string[256];index,count:integer):string[256]; external;
+function copy(s:string;index,count:integer):string; external;
-procedure insert(ins:string[256]; var dest:string[256]; position:integer); external;
+procedure insert(ins: string; var dest: string; position:integer); external;
 procedure delete(var s:string; from:integer; count:integer); external;
 function pos(substr:string;var s:string):integer; external;
 function pwroften(exp:integer):real; external;
@ -207,7 +205,7 @@ procedure readvolumeblks(volumeid:integer; destbuf:^iobuffer; blkno:integer; blk
 procedure writevolumeblks(volumeid:integer; srcbuf:^iobuffer; blkno:integer; blkCount: integer; var error:integer);
 	external;
 function findvolume(name:string):integer; external;
-procedure openvolumeid(volid:integer;var error:integer); external;
+procedure openvolumeid(volid:integer); external;
 procedure closevolumeid(volid:integer); external;
 function IOResult(var fil:file):integer; external;
 function ErrorStr(err:integer):string; external;
@ -242,7 +240,6 @@ procedure freadreal(var v:real;var f:file); external;
 procedure openchannel(name:filenamestr; var f:file; mode:filemode; var error:integer); external;
 procedure open(var f:file; name:pathnamestr; mode: filemode); external;
 procedure noecho(var f:file; noecho:boolean; var old:boolean); external;
 procedure nointr(var f:file; aBool:boolean; var old:boolean); external;
 procedure intstr(v:integer; fieldWith:integer; var rbuf:string);
 	external;
@ -272,8 +269,8 @@ procedure TextDefault; external;
 procedure PTerm; external; (* from runtime.s *)
 procedure PExec(prgfile:pathnamestr; var args:PArgVec; argCount:integer;var error:integer); external;
-procedure PExec1(prgfile:pathnamestr; arg1:string; var error:integer); external;
+procedure PExec2(prgfile:pathnamestr; arg1:string; var error:integer); external;
-procedure PExec2(prgfile:pathnamestr; arg1, arg2:string; var error:integer); external;
+procedure PExec3(prgfile:pathnamestr; arg1, arg2:string; var error:integer); external;
 function ParamStr(i:integer):string; external;
 function ParamCount():integer; external;
--- a/lib/stdlib.pas
+++ b/lib/stdlib.pas
@ -26,9 +26,8 @@ const IONoError 	=  0;
      IOReadOnly 	=  8;
      IOInvalidOp	=  9;
      IOInvalidFormat   = 10;
-      IONoMem		= 11;
+      IOUserIntr	= 11;
-      IOUserIntr	= 12;
+      IOMaxErr          = 11;
      IOMaxErr          = 12;
 const PArgMax = 7;
@ -48,7 +47,7 @@ type file = record
 			ateof:boolean;
 			noecho:boolean; (* read chars are not echoed *)
 			raw:boolean;  (* turn off backspace processing on input, CR processing on output *)
-			nointr:boolean); (* turn off keyboard interrupt character processing *)
+			nointr: boolean); (* turn off keyboard interrupt character processing *)
 		IODiskFile: (volumeid: integer;fileno: integer; filpos:integer; bufStart:integer;
 				size:integer; sizeExtents:integer;
@ -134,7 +133,7 @@ var DefaultVolumeId:integer;
 		character to the runtime error routine
 		which takes null-terminated strings.
 	*)
-var ioerrordesc: array [0..IOMaxErr] of string[20] = (
+var ioerrordesc: array [0..11] of string[20] = (
 	'No error',
        'File not found',
 	'Volume not found',
@ -146,14 +145,13 @@ var ioerrordesc: array [0..IOMaxErr] of string[20] = (
 	'File is readonly',
 	'Invalid operation',
 	'Invalid format',
 	'Not enough memory',
 	'Interrupted by user'
 	);
    matherror:string[38] = 'Invalid argument to sqrt/ln/tan/cotan';
    pexecerror:string[28]= 'Invalid arguments for PExec';
-    random_state:integer = -42;
+    random_state:integer;
    PArgs:array [0..PArgMax] of string external;
    PArgCount:integer external;
@ -404,7 +402,7 @@ begin
 	GetCurTimestamp := GetTimestamp(now);
 end;
-function copy(s:string[256];index,count:integer):string[256];
+function copy(s:string;index,count:integer):string;
 var len:integer;
 begin
 	copy := '';
@ -418,7 +416,7 @@ begin
 	end;
 end;
-procedure insert(ins:string[256]; var dest:string[256]; position:integer);
+procedure insert(ins: string; var dest: string; position:integer);
 var i,count,from,to_:integer;
 begin
 	if position < 1 then position := 1;
@ -482,9 +480,6 @@ end;
   That means you cannot use pos to search inside a string
   literal. Hopefully this is not something you want to do.
   *)
 (* TODO: UCSD-Pascal and TP3.0 specs say, searched string
   is a string expression so cannot be var parameter *)
 function pos(substr:string;var s:string):integer;
 var substrlen:integer;
    slen:integer;
@ -1184,18 +1179,8 @@ ext:
 		v := x;
 		code := 0;
 	end
 	else
 	begin
 		if i = 1 then  (* empty string gives error position 1 *)
 			code := 1
 	else
 		code := i - 1;
 	end;
 end;
 procedure errorhalt(var fil:file);
 begin
 	RuntimeError(ioerrordesc[fil.lastError]);
 end;
 procedure checkerror(var fil:file);
@ -1203,7 +1188,7 @@ begin
 	if fil.lastError <> 0 then
 	begin
 		if not fil.errorAck then
-			errorhalt(fil)
+			RuntimeError(ioerrordesc[fil.lastError])
 		else
 		begin
 			fil.lastError := 0;
@ -1346,16 +1331,12 @@ procedure freadreal(var v:real;var f:file);
 var buf:string[40];
    errpos:integer;
 begin
 	errpos := -1;
 	fskipwhite(f);
 	fscanbuf(f,ScanReal, buf);
 	if f.lastError = 0 then
 		val(buf, v, errpos);
 	if errpos <> 0 then
 	begin
 		fileerror(f, IOInvalidFormat);
 		checkerror(f);
 	end;
 end;
 procedure freadstring(var s:string; var f:file);
@ -1368,7 +1349,7 @@ var aChar:char;
 begin
 	repeat
 		aChar := freadchar(aFile);
-	until eoln(aFile); (* eoln checks for cr, lf and eof *)
+	until (aChar = #13) or eof(aFile);
 	(*
 		If it is a disk file, try to read the
@ -1556,17 +1537,13 @@ begin
 	end;
 end;
-procedure openvolumeid(volid:integer;var error:integer);
+procedure openvolumeid(volid:integer);
 begin
 	error := 0;
 	with volumeTable[volid] do
 	begin
 		if dirCache = nil then
-			newOrNil(dirCache);
+			new(dirCache);
-		if dirCache <> nil then
+		openFilesCount := openFilesCount + 1;
 			openFilesCount := openFilesCount + 1
 		else
 			error := IONoMem;
 	end;
 end;
@ -1685,21 +1662,12 @@ begin
 	{ writeln('  readbuf data: ', fil.buffer^[0][0]); }
 end;
 procedure close(var aFile:file); forward;
 (* Set error state on file and close it.
   Buffer will not be flushed as that might
   have caused the error.
 *)
 procedure fileerror(var fil:file; error:integer);
 begin
 	(* should check if there was an error already
 	   and throw a runtime error in that case *)
 	fil.lastError := error;
 	fil.errorAck := false;
 	if fil.buffer <> nil then
 	begin
 		fil.needsflush := false;
 		close(fil);
 	end;
 end;
 function IOResult(var fil:file):integer;
@ -1844,8 +1812,6 @@ end;
 function filesize(var fil:file):integer;
 begin
 	checkerror(fil);
 	if fil.typ = IOChannel then
 		filesize := -1
 	else
@ -2044,11 +2010,7 @@ begin
 	aFile.typ := IODiskFile;
 	aFile.mode := mode;
-	newOrNil(aFile.buffer);
+	new(aFile.buffer);
 	if aFile.buffer = nil then
 		fileerror(aFile, IONoMem)
 	else
 	begin
 	aFile.bufpos := 0;
 	aFile.bufsize := DefaultBufSize;
 	aFile.needsflush := false;
@ -2065,7 +2027,6 @@ begin
 	aFile.extentBlocks := extentSize div 512;
 	seek(aFile,0);
 	end;
 end;
 procedure updatedirslot(var aFile:file);
@ -2088,22 +2049,19 @@ procedure close(var aFile:file);
 begin
 	if aFile.typ = IODiskFile then
 	begin
 		if aFile.lastError = IOFileClosed then
 			errorhalt(aFile);
 		{ writeln('close needsflush:', aFile.needsflush, ' changed:', aFile.changed, ' error:', aFile.lastError); }
 		if aFile.needsflush then
 			flushfile(aFile);
-
+		if aFile.lastError = 0 then
 		begin
 			fileerror(aFile, IOFileClosed);
 			{ writeln('close f.buffer:', aFile.buffer); }
 			dispose(aFile.buffer);
 			aFile.buffer := nil;
 		if aFile.lastError = 0 then
 		begin
 			if aFile.changed then
 				updatedirslot(aFile);
-			if aFile.lastError = 0 then
+
 				fileerror(aFile, IOFileClosed);
 		end;
 		closevolumeid(aFile.volumeid);
@ -2282,8 +2240,7 @@ begin
 	if volid > 0 then
 	begin
-		openvolumeid(volid, error);
+		openvolumeid(volid);
 		if error = 0 then
 		slotno := findfile(volid, fname, dirs, error)
 	end
 	else
@ -2603,16 +2560,6 @@ begin
 	end;
 end;
 procedure nointr(var f:file;aBool:boolean;var old:boolean);
 begin
 	if f.typ <> IOChannel then
 		fileerror(f, IOInvalidOp)
 	else
 	begin
 		old := f.nointr;
 		f.nointr := aBool;
 	end;
 end;
 (*
  implementation of Xorshift algorithm by George Marsaglia,
  see: Marsaglia, George (July 2003).
@ -2649,7 +2596,6 @@ begin
 		if ord(aChar) <= ord('z') then
 			upcase := chr(ord(aChar) - 32)
 		else
 			upcase := aChar
 	else
 		upcase := aChar;
 end;
@ -2715,14 +2661,14 @@ begin
 	end;
 end;
-procedure PExec1(prgfile:pathnamestr; arg1:string; var error:integer);
+procedure PExec2(prgfile:pathnamestr; arg1:string; var error:integer);
 var args:PArgVec;
 begin
 	args[0] := arg1;
 	PExec(prgfile, args, 1, error);
 end;
-procedure PExec2(prgfile:pathnamestr; arg1, arg2:string; var error:integer);
+procedure PExec3(prgfile:pathnamestr; arg1, arg2:string; var error:integer);
 var args:PArgVec;
 begin
 	args[0] := arg1;
--- a/pcomp/Makefile
+++ b/pcomp/Makefile
@ -1,45 +1,47 @@
 PCOMP=./pcomp
 SASM=./sasm
 LSYMGEN=./lsymgen
 LIBGEN=./libgen
 .SUFFIXES:
-.SUFFIXES: .pas .o .s .prog
+.SUFFIXES: .pas .o
 .pas.s:
 	$(PCOMP) $<
 .s.prog:
 	$(SASM) $<
 .pas:
 	fpc -Mobjfpc -gl $<
-all: libs pcomp sasm sdis lsymgen shortgen nativecomp nativeprogs
+all: pcomp sasm sdis libgen lsymgen
-libs: pcomp sasm lsymgen shortgen
+libs: pcomp sasm lsymgen libgen
 	$(SASM) ../lib/coreloader.s
 	$(LSYMGEN) ../lib/coreloader.sym
 	$(PCOMP) -n ../lib/stdlib.pas
-	$(SASM) ../lib/stdlibwrap.s ../lib/stdlib.lib
+	$(LIBGEN) ../lib/stdlib.s
-	$(LSYMGEN) ../lib/stdlibwrap.sym ../lib/stdlib.lsym
+	$(LIBGEN) ../lib/runtime.s
 	$(LIBGEN) ../lib/float32.s
-test: libs sasm.s pcomp.s lsymgen.s shortgen.s
+nativecomp: pcomp sasm libs
 	$(PCOMP) sasm.pas
 	$(PCOMP) pcomp.pas
 	$(PCOMP) lsymgen.pas
 	$(PCOMP) libgen.pas
-testprgs: libs sasm.prog pcomp.prog lsymgen.prog shortgen.prog
+nativeprogs: nativecomp
-
+	$(PCOMP) ../progs/shell.pas
-nativecomp: libs pcomp.prog sasm.prog lsymgen.prog shortgen.prog
+	$(PCOMP) ../progs/editor.pas
-
+	$(PCOMP) ../progs/reclaim.pas
-nativeprogs: pcomp ../progs/shell.prog ../progs/editor.prog ../progs/reclaim.prog \
+	$(PCOMP) ../progs/dumpdir.pas
-        ../progs/dumpdir.prog ../progs/partmgr.prog ../progs/xfer.prog \
+	$(PCOMP) ../progs/partmgr.pas
-        ../progs/recover.prog ../progs/changemem.prog
+	$(PCOMP) ../progs/xfer.pas
 	$(SASM) ../lib/rommon.s
 	$(SASM) -A ../lib/rommon.s ../lib/rom.mem
-
+examples: nativecomp
-examples: nativecomp ../tests/readtest.prog ../tests/readchartest.prog ../tests/timetest.prog \
+	$(PCOMP) ../tests/readtest.pas
-	../tests/test133.prog ../tests/cchangetest.prog ../tests/tree.prog
+	$(PCOMP) ../tests/readchartest.pas
 	$(PCOMP) ../tests/timetest.pas
 	$(PCOMP) ../tests/test133.pas
 	-$(PCOMP) ../examples/chase.pas
-	-$(SASM) ../examples/chase.s
+	$(PCOMP) ../tests/cchangetest.pas
-	-$(MAKE) -C ../rogue -f Makefile.tridoracpu
+	$(PCOMP) ../tests/tree.pas
 clean:
-	rm -f pcomp sasm sdis libgen lsymgen shortgen*.o *.s *.prog \
+	rm -f pcomp sasm sdis libgen lsymgen *.o *.s
 		../lib/stdlib.s ../lib/stdlib.lib ../lib/stdlib.lsym
--- a/pcomp/emit.pas
+++ b/pcomp/emit.pas
@ -111,7 +111,7 @@ begin
 	emitIns2('BRANCH','@+2');	(* NOP, to make alignment explicit *)
 	emitIns('.CPOOL');			(* header/prologue + 2 constants is 32 bytes *)
-	if useStdlib and not useStandalone then
+	if useStdlib then
 	begin
 		writeln(outfile, '%include "stdlib.lsym"');
 		writeln(outfile, '%incbin "stdlib.lib"');
@ -312,21 +312,14 @@ begin
 	emitArrayConsts;
 	if useStandalone then
-	begin
+		emitInclude('corelib.s')
 		emitInclude('corelib.s');
 		emitInclude('runtime.s');
 		emitInclude('float32.s');
 		emitInclude('stdlib.s');
 	end
 	else
 		emitInclude('coreloader.lsym');
 	rewindStringList(usedUnits);
 	while nextStringListItem(usedUnits, unitName) do
 		emitInclude(unitName + UnitSuffix2);
-	(* _END label needs to be word-aligned because
+
 		it is used as the start of the heap *)
 	emitIns('.ALIGN');
 	emitLabelRaw('_END');
 end;
@ -1066,7 +1059,6 @@ end;
   *)
 procedure emitProcedureCall(aProc: ProcRef);
 var procLabel: IdentString;
 	i:integer;
 begin
 	(* pass pointer to stackframe of caller for nested procedures *)
 	if aProc^.isNested then
@ -1077,17 +1069,9 @@ begin
 		if aProc^.level > curProcedure^.level then
 			emitIns2('LOADREG','FP')
 		else
-		begin
+			(* TODO: calling nested aProc with a lower nesting level.
-			(*  Calling nested aProc with a lower nesting level.
+				need to chase a chain of old BP pointers. *)
-				Need to chase a chain of old BP pointers. *)
+			errorExit2('internal error: outward call of nested aProc not implemented', '');
 			emitIns2('LOADREG', 'BP');
 			(*	BP points to the stackframe of the outer procedure,
 				@BP contains the stackframe of the procedure one step further
 					outwards, and so on.
 			*)
 			for i := aProc^.level + 1 to curProcedure^.level do
 				emitIns('LOADI');
 		end;
 	end;
 	emitFpAdjust(-curProcedure^.tempsSize);
@ -1266,7 +1250,7 @@ begin
 		(* nothing to do *)
 	end
 	else
-	if (amount > 0) and (amount <= MaxTinyOffset) then
+	if amount <= MaxTinyOffset then
 		emitIns2Int('INC', amount)
 	else
 	begin
@ -1282,7 +1266,7 @@ begin
 		(* nothing to do *)
 	end
 	else
-	if (amount > 0) and (amount <= MaxTinyOffset) then
+	if amount <= MaxTinyOffset then
 		emitIns2Int('DEC', amount)
 	else
 	begin
--- a/pcomp/make.bat
+++ b/pcomp/make.bat
@ -17,7 +17,7 @@ rem exit /b
 py pcomp.py sasm.pas
 py pcomp.py pcomp.pas
 py pcomp.py lsymgen.pas
-py pcomp.py shortgen.pas
+py pcomp.py libgen.pas
 rem exit /b
@ -27,8 +27,6 @@ py pcomp.py ..\progs\reclaim.pas
 py pcomp.py ..\progs\dumpdir.pas
 py pcomp.py ..\progs\partmgr.pas
 py pcomp.py ..\progs\xfer.pas
 py pcomp.py ..\progs\recover.pas
 py pcomp.py ..\progs\changemem.pas
 sasm ..\lib\rommon.s
 sasm -A ..\lib\rommon.s ..\lib\rom.mem
@ -41,11 +39,3 @@ py pcomp.py ..\tests\test133.pas
 py pcomp.py ..\examples\chase.pas
 py pcomp.py ..\tests\cchangetest.pas
 py pcomp.py ..\tests\tree.pas
 if not exist ..\rogue\rogue.pas exit /b
 cd ..\rogue
 ..\pcomp\pcomp rogue.pas
 ..\pcomp\sasm rogue.s
 cd ..\pcomp
--- a/pcomp/pcomp.pas
+++ b/pcomp/pcomp.pas
@ -1,6 +1,4 @@
 (* Copyright 2021-2024 Sebastian Lederer. See the file LICENSE.md for details *)
 {$H600}
 {$S64}
 program PascalCompiler;
 {$R+}
 {$!}{$ifdef FPC}uses math,crt;{$endif}
@ -43,7 +41,7 @@ type 	TokenType = (
 		ArrayType, RecordType, PointerType, StringCharType, EnumType, 
 		SetType, UnresolvedType );
-	SpecialProc = ( NoSP, NewSP, New0SP, DisposeSP, ReadSP, WriteSP, ReadlnSP, WritelnSP,
+	SpecialProc = ( NoSP, NewSP, DisposeSP, ReadSP, WriteSP, ReadlnSP, WritelnSP,
 			SetlengthSP, ValSP, StrSP, ExitSP );
 	SpecialFunc = ( NoSF, TruncSF, FracSF, IntSF, SqrSF, SuccSF, PredSF,
 			OddSF, ChrSF, OrdSF, AbsSF);
@ -263,7 +261,7 @@ const	insSize = 2;
 		MaxIncludes = 4;
 		StdLibName = 'stdlib';
 		UnitSuffix1 = '.inc';
-		UnitSuffix2 = '.s';
+		UnitSuffix2 = '.lib';
 		FilenameSuffix = '.pas';
 		OutfileSuffix = '.s';
 		InputFileName = 'INPUT';
@ -291,7 +289,7 @@ var
 		'UNIT', 'IMPLEMENTATION', 'INTERFACE', 'USES',
 		'_' );
 		specialprocnames: array [SpecialProc] of string[12] = (
-			'_', 'NEW', 'NEWORNIL', 'DISPOSE', 'READ', 'WRITE', 'READLN', 'WRITELN', 'SETLENGTH',
+			'_', 'NEW', 'DISPOSE', 'READ', 'WRITE', 'READLN', 'WRITELN', 'SETLENGTH',
 			'VAL','STR', 'EXIT');
 		specialfuncnames: array [SpecialFunc] of string[8] = (
 			'_', 'TRUNC', 'FRAC', 'INT', 'SQR', 'SUCC', 'PRED', 'ODD',
@ -2186,7 +2184,7 @@ begin
 	if ch = '!' then
 	(* special comment till end of line *)
 	begin
-		while not (nextChar in [#13, #10]) do (* nothing *);
+		while not (nextChar = #13) do (* nothing *);
 		readNextToken;
 	end
 	else
@ -2456,7 +2454,10 @@ begin
 	begin
 		digits := curToken.tokenText;
 		if matchTokenOrNot(MinusToken) then
 		begin
 			readNextToken;
 			digits := digits + curToken.tokenText;
 		end;
 		parseInteger := integerFromString(digits);
 	end;
 	readNextToken;
@ -2809,8 +2810,6 @@ begin
 		if checkToken(CommaToken) then
 		begin
 			(* TODO: handle comma syntax for indexing a char
 				from an array of strings *)
 			if elType.baseType <> ArrayType then
 				errorExit2('invalid array subscript for', name)
 		end;
@ -3230,22 +3229,10 @@ begin
 	readNextToken;
 end;
 (* Handle an array range part. Very similar to parseInteger
   but additionally handles Boolean, Enum and Char types which
   can be used for array indices *)
 procedure getRangePart(var value:integer; var typeReturn: TypeSpec);
 var cnst: ConstRef;
    negate:boolean;
 	digits: string[12];
 begin
 	setBaseType(typeReturn, NoType);
 	negate := false;
 	if checkToken(MinusToken) then
 	begin
 		negate := true;
 		readNextToken;
 	end;
 	if checkToken(IdentToken) then
 	begin
@ -3279,11 +3266,7 @@ begin
 	else
 	begin
 		setBaseType(typeReturn, IntegerType);
-		digits := curToken.tokenText;
+		value := parseInteger;
 		if negate then
 			insert('-', digits, 1);
 		value := integerFromString(digits);
 		readNextToken;
 	end;
 end;
@ -3448,9 +3431,9 @@ begin
 				if savedType.baseType = NoType then
 					savedType := elementType;
 				emitLoadConstantInt(cnst^.intValue);
 				readNextToken;
 			end;
 			emitAddToSet;
 			readNextToken;
 		end
 		else if checkToken(NumberToken) then
 		begin
@ -4014,8 +3997,6 @@ begin
 		begin
 			readNextToken;
 			length := parseInteger;
 			if length < 1 then
 				errorExit2('invalid string length', '');
 			matchToken(RBracketToken);
 		end;
 		typSpec.size := getStringMemSize(length);
@ -4500,7 +4481,7 @@ begin
 	isFunction := aProc^.returnType.baseType <> NoType;
 end;
-procedure parseNew(checkNil:boolean);
+procedure parseNew;
 var memLoc: MemLocation;
    typeReturn: TypeSpec;
 begin
@ -4526,17 +4507,17 @@ begin
 		emitLoadConstantInt(memLoc.typ.pointedType^.size);
 		emitMemAlloc;
 		if typeContainsString(memLoc.typ.pointedType^) then
 			emitClearAlloc(memLoc.typ.pointedType);
 	end;
 	emitCheckAlloc;
 	(*We need to call CLEARMEM when the allocated type
 		contains strings.
 		INITSTRING checks if the header is non-zero to see if
 		the string is already initialized, and the allocated
 		chunk might contain random data so it would look
 		like an initialized string. *)
 		if typeContainsString(memLoc.typ.pointedType^) then
 			emitClearAlloc(memLoc.typ.pointedType);
 	end;
 	if checkNil then
 		emitCheckAlloc;
 	writeVariable(memLoc);
@ -5017,9 +4998,7 @@ begin
 	NoSP:
 		errorExit2('internal error in parseSpecialProcCall', lastToken.tokenText);
 	NewSP:
-		parseNew(true);
+		parseNew;
 	New0SP:
 		parseNew(false);
 	DisposeSP:
 		parseDispose;
 	ReadSP:
@ -5832,19 +5811,6 @@ begin
 	matchToken(ColonToken);
 end;
 procedure parseGotoStatement;
 var aLabl: LablRef;
 begin
 	readNextToken;
 	matchToken(IdentToken);
 	aLabl := findLabel(curProcedure, lastToken.tokenText);
 	if aLabl = nil then
 		errorExit2('GOTO to undefined label', lastToken.tokenText);
 	if curProcedure^.estackCleanup > 0 then
 		errorExit2('GOTO not allowed inside FOR or CASE', '');
 	emitLabelJump(aLabl);
 end;
 procedure parseStatement;
 var sym: SymblRef;
 	cnst: ConstRef;
@ -5870,7 +5836,13 @@ begin
 	end;
 	if checkToken(GotoToken) then
-		parseGotoStatement
+	begin
 		readNextToken;
 		matchToken(IdentToken);
 		aLabl := findLabel(curProcedure, lastToken.tokenText);
 		if aLabl = nil then errorExit2('GOTO to undefined label', lastToken.tokenText);
 		emitLabelJump(aLabl);
 	end
 	else
 	if checkToken(IfToken) then
 		parseIfStatement
--- a/pcomp/sasm.pas
+++ b/pcomp/sasm.pas
@ -1,7 +1,7 @@
 (* Copyright 2021-2024 Sebastian Lederer. See the file LICENSE.md for details *)
 {$MODE objfpc}
 {$H600}
-{$S32}
+{$S4}
 program sasm;
 {$!}{$ifdef FPC}uses math,crt;{$endif}
 {$R+}
@ -1515,6 +1515,8 @@ begin
 		end;
 		if dref^.symboldata.value <> value then
 			(* writeln('////// label changed value ', keyword, ' ',
 				dref^.symboldata.value, ' -> ', value); *)
 		dref^.symboldata.value := value;
 	end;
 end;
@ -1870,9 +1872,9 @@ begin
 		if (pc and 3) = 0 then	(* no padding *)
 		begin
 			pad := false;
-			(* total size 10 bytes *)
+			(* total size 8 bytes *)
 			offset := 4;	(* offset for LOADREL *)
-			shrinkage := 8; (* difference to short form size *)
+			shrinkage := 6; (* difference to short form size *)
 		end
 		else
 		begin
@ -1890,17 +1892,9 @@ begin
 		encodeInstruction('JUMP', 0, encoded);
 		emitInstructionWord(encoded);
 		(* Padding is always done, so the length of the sequence does
 			not change depending on the position. The pad is either
 			placed before the address to align it on a word address,
 			or after, if it is already aligned. *)
 		if pad then
 			emitInstructionWord(0);
 		emitWord(value);
 		if not pad then
 			emitInstructionWord(0);
 	end
 	else
 	begin
@ -1943,9 +1937,9 @@ begin
 		if (pc and 3) = 2 then (* no padding *)
 		begin
 			pad := false;
-			(* total size 12 bytes *)
+			(* total size 10 bytes *)
 			offset := 4;	(* offset for LOADREL *)
-			shrinkage := 10; (* difference to short form size *)
+			shrinkage := 8; (* difference to short form size *)
 		end
 		else
 		begin
@ -1973,17 +1967,9 @@ begin
 		encodeInstruction('JUMP', 0, encoded);
 		emitInstructionWord(encoded);
 		(* Padding is always done, so the length of the sequence does
 			not change depending on the position. The pad is either
 			placed before the address to align it on a word address,
 			or after, if it is already aligned. *)
 		if pad then
 			emitInstructionWord(0);
 		emitWord(value);
 		if not pad then
 			emitInstructionWord(0);
 	end
 	else
 	begin
@ -2056,9 +2042,6 @@ begin
 			operandValue := 0;
 		emitBlock(count, operandValue);
 	end
 	else
 	if lastToken.tokenText = '.ALIGN' then
 		alignOutput(wordSize)
 	else
 		errorExit2('Unrecognized directive', lastToken.tokenText);
 end;
--- a/pcomp/shortgen.pas
+++ b/pcomp/shortgen.pas
@ -5,7 +5,7 @@ const	shortcutChar = '`';
 	firstShCChar = 'A';
 	lastShCChar = 'i';
-	OutfileSuffix = '.cs';
+	OutfileSuffix = '.lib';
 {$I 'platfile-types+.pas'}
--- a/progs/changemem.pas
+++ b/progs/changemem.pas
@ -1,173 +0,0 @@
 program changemem;
 const ProgramMagic = $00100AFE;
 type ProgramHeader = record
 		magic:integer;
 		heapSize:integer;
 		stackSize:integer;
 		mainPtr:integer;
 	end;
 var filename:string;
    h:ProgramHeader;
 procedure showHex(value:integer);
 var i:integer;
    digit:integer;
    digits:array[1..8] of char;
    ch:char;
 begin
 	for i := 1 to 8 do
 	begin
 		digit := value and 15;
 		value := value shr 4;
 		if digit < 10 then
 			ch := chr(digit + ord('0'))
 		else
 			ch := chr(digit - 10 + ord('A'));
 		digits[i] := ch;
 	end;
 	for i := 8 downto 1 do
 		write(digits[i]);
 end;
 procedure showValue(labl:string; value:integer);
 begin
 	write(labl:20, ' ');
 	write(value:8, ' (');
 	showHex(value);
 	writeln(')');
 end;
 procedure showHeader(var h:ProgramHeader);
 begin
 	showValue('heap size', h.heapSize);
 	showValue('stack size', h.stackSize);
 	showValue('main entry point', h.mainPtr);
 end;
 procedure readHeader(var filename:string;var h:ProgramHeader);
 var f:file;
 begin
 	writeln('reading file ', filename);
 	open(f, filename, ModeReadOnly);
 	if IOResult(f) <> 0 then
 	begin
 		writeln('Error opening file: ', ErrorStr(IOResult(f)));
 		halt;
 	end
 	else
 	begin
 		read(f, h);
 		if IOResult(f) <> 0 then
 		begin
 			writeln('Error reading header: ', ErrorStr(IOResult(f)));
 			halt;
 		end;
 		close(f);
 	end;
 end;
 procedure writeHeader(var filename:string;var h:ProgramHeader);
 var f:file;
 begin
 	writeln('writing file ', filename);
 	open(f, filename, ModeModify);
 	if IOResult(f) <> 0 then
 	begin
 		writeln('Error opening file: ', ErrorStr(IOResult(f)));
 		halt;
 	end
 	else
 	begin
 		write(f, h);
 		if IOResult(f) <> 0 then
 		begin
 			writeln('Error writing header: ', ErrorStr(IOResult(f)));
 			halt;
 		end;
 		close(f);	
 	end;
 end;
 procedure modifyHeader(var filename:string;var h:ProgramHeader);
 var done:boolean;
    ch:char;
    changed:boolean;
 	function getNewValue(descr:string):integer;
 	var buf:string;
 	    v,e:integer;
 	begin
 		getNewValue := 0;
 		write('New ',descr, ' size (decimal)> ');
 		readln(buf);
 		val(buf, v, e);
 		if(e > 0 ) or (v <= 0) then
 			writeln('invalid size')
 		else
 			getNewValue := v;
 	end;
 	procedure changeStackSize;
 	var v:integer;
 	begin
 		v := getNewValue('stack');
 		if v > 0 then
 		begin
 			h.stackSize := v;
 			changed := true;
 		end;	
 	end;
 	procedure changeHeapSize;
 	var v:integer;
 	begin
 		v := getNewValue('heap');
 		if v > 0 then
 		begin
 			h.heapSize := v;
 			changed := true;
 		end;
 	end;
 begin
 	changed := false; done := false;
 	while not done do
 	begin
 		writeln(filename, ' header:');
 		showHeader(h);
 		writeln('Change H)eap size   Change S)tack size   eX)it');
 		write('> ');
 		read(ch);
 		writeln;
 		case upcase(ch) of
 		'S': changeStackSize;
 		'H': changeHeapSize;
 		'X': done := true;
 		else
 			writeln('invalid command');
 		end;
 	end;
 	if changed then
 		writeHeader(filename, h);
 end;
 begin
 	if ParamCount > 0 then
 		filename := ParamStr(1)
 	else
 	begin
 		write('File name> ');
 		readln(filename);
 	end;
 	readHeader(filename, h);
 	if h.magic <> ProgramMagic then
 		writeln('invalid magic value ', h.magic)
 	else
 		modifyHeader(filename, h);
 end.
--- a/progs/dumpdir.pas
+++ b/progs/dumpdir.pas
@ -14,8 +14,8 @@ var dirs:DirectorySlot;
    error:integer;
 begin
 	lastSlot := volumeTable[volid].part.dirSize - 1;
-	openvolumeid(volid, error); (* we just ignore error here because
+	openvolumeid(volid);
-		we should always have enough heap space *)
+
 	for i := 0 to lastSlot do
 	begin
 		getdirslot(volid, i, dirs, error);
--- a/progs/editor.pas
+++ b/progs/editor.pas
@ -8,7 +8,7 @@ const COMPILERPROG = '#SYSTEM:pcomp.prog';
 const MAX_LENGTH = 512;
      MAX_LINES = 10000;
      MAX_SCREENH = 256;
-      MAX_KEYWORD = 33;
+      MAX_KEYWORD = 31;
      MAX_CLIPB_SIZE = 300;
@ -94,14 +94,14 @@ var lines: array [1..MAX_LINES] of ^linestr;
    catColors: array [Unknown..StrLit] of integer =
 	( TEXT_FG, 0, KEYWORD_FG, IDENT_FG, NUM_FG, PUNCT_FG, COMMENT_FG, STRLIT_FG );
-    keywords: array [0..MAX_KEYWORD] of string[12] = (
+    keywords: array [0..MAX_KEYWORD] of string[20] = (
-			'AND', 'ARRAY', 'BEGIN', 'BOOLEAN', 'CASE', 'CHAR', 'CONST',
+			'VAR', 'IF', 'THEN', 'ELSE', 'BEGIN', 'END', 'PROCEDURE', 'FUNCTION',
-			'DIV', 'DO', 'ELSE', 'END', 'FOR', 'FUNCTION', 'IF', 'IN', 'INTEGER',
+			'WHILE', 'FOR', 'DO', 'IN', 'OF', 'CASE', 'TO', 'REPEAT', 'UNTIL',
-			'MOD', 'NOT', 'OF', 'OR', 'PROCEDURE', 'PROGRAM',
+			'CHAR', 'INTEGER', 'REAL', 'BOOLEAN', 'ARRAY', 'RECORD', 'STRING',
-			'REAL', 'RECORD', 'REPEAT', 'STRING', 'THEN', 'TO', 'TYPE',
+			'MOD', 'DIV', 'AND', 'OR', 'NOT',
-			'UNIT', 'UNTIL', 'USES', 'VAR', 'WHILE'
+			'TYPE', 'CONST',
 			'PROGRAM'
 		);
    keywordIdx: array ['A'..'Z'] of integer;
    paramPos:integer;
    errorLine:integer;
    errorMsg:string;
@ -137,8 +137,7 @@ end;
 procedure getScreenSize;
 var c:char;
 begin
-	(* empty keyboard buffer to make sure GetTermSize
+	(* empty keyboard buffer *)
 		can read the response from the terminal *)
 	while conavail do read(con, c);
 	GetTermSize(screenW, screenH);
@ -678,6 +677,30 @@ begin
 	hscroll;
 end;
 function isKeyword(var s:string):boolean;
 var i:integer;
    c:char;
    upBuf:string[MAX_LENGTH];
 begin
 	isKeyword := false;
 	if highlight then
 	begin
 		upBuf := '';
 		for c in s do appendchar(upBuf,upcase(c));
 		for i := 0 to MAX_KEYWORD do
 		begin
 			if keywords[i] = upBuf then
 			begin
 				isKeyword := true;
 				break;
 			end;
 		end;
 	end;
 end;
 function isalpha(c:char):boolean;
 begin
 	isalpha :=	((ord(c) >= ord('A')) and (ord(c) <= ord('Z'))) or
@ -692,39 +715,6 @@ begin
 			((ord(c) >= ord('[')) and (ord(c) <= ord('^')));
 end;
 function isKeyword(var s:string):boolean;
 var i:integer;
    start:integer;
    c,f:char;
    upBuf:string[MAX_LENGTH];
 begin
 	isKeyword := false;
 	if highlight then
 	begin
 		upBuf := '';
 		for c in s do appendchar(upBuf,upcase(c));
 		(* use the first letter of the search string
 			for our starting index *)
 		c := upBuf[1];
 		if isalpha(c) then
 		begin
 			start := keywordIdx[c];
 			for i := start to MAX_KEYWORD do
 			begin
 				f := keywords[i][1];
 				if c <> f then break;
 				if keywords[i] = upBuf then
 				begin
 					isKeyword := true;
 					break;
 				end;
 			end;
 		end;
 	end;
 end;
 function getCat(c:char):HiliteCat;
 begin
 	if isalpha(c) then
@ -1662,10 +1652,11 @@ end;
 procedure gotoLine(l:integer);
 begin
 	if l < 1 then
 		l := 1
 	else
 	if l > lineCount then
 		l := lineCount;
 	if l < 1 then
 		l := 1;
 	topY := l - (screenH div 2);
 	if topY < 1 then
@ -1713,7 +1704,7 @@ var error:integer;
 begin
 	success := true;
 	if isModified then
-		writeFile(success);
+		save;
 	if success then
 	begin
 		if isAsmFile(filename) then
@ -2426,23 +2417,6 @@ begin
 	end;
 end;
 procedure initKeywordIdx;
 var i:integer;
    ch, lastCh:char;
 begin
 	lastCh := #0;
 	for i := 0 to MAX_KEYWORD do
 	begin
 		ch := keywords[i][1];
 		if ch <> lastCh then
 		begin
 			keywordIdx[ch] := i;
 			lastCh := ch;
 		end;
 	end;
 end;
 begin
 	errorLine := 0;
 	paramPos := 1;
@ -2450,8 +2424,6 @@ begin
 	autoindent := true;
 	keepClips := false;
 	initKeywordIdx;
 	while paramPos <= ParamCount do
 	begin
 		if paramStr(paramPos) = '-l' then
--- a/progs/reclaim.pas
+++ b/progs/reclaim.pas
@ -62,13 +62,8 @@ begin
 	begin
 		if lastUsed < endSlot then
 		begin
 			(* if the volume is empty mark the first slot *)
 			if lastUsed = 0 then
 				slotNo := reservedCount
 			else
 				slotNo := lastUsed + 1;
 			writeln('Updating directory...');
 			slotNo := lastUsed + 1;
 			getdirslot(volid, slotNo, dirslot, error);
 			if error <> IONoError then
 			begin
@ -123,9 +118,8 @@ begin
 		freeAreaCount := 0;
 		lastUsed := 0;
-		openvolumeid(volid, error);
+		openvolumeid(volid);
-			(* ignoring theoretically possible out-of-heap-error *)
+		i := volumeTable[volid].startSlot;
 		i := 0;
 		endSlot := volumeTable[volid].part.dirSize - 1;
 		if verbose then
@ -309,7 +303,7 @@ begin
 		writeln('Volume ', volname, ' not found.')
 	else
 	begin
-		openvolumeid(volid, error);
+		openvolumeid(volid);
 		endSlot := volumeTable[volid].part.dirSize - 1;
 		extentSize := volumeTable[volid].part.extentSize;
--- a/progs/recover.pas
+++ b/progs/recover.pas
@ -1,167 +0,0 @@
 (* Copyright 2025 Sebastian Lederer. See the file LICENSE.md for details *)
 program recover;
 const PageMargin = 4;
 var filename:string;
    volid:integer;
 (* we use some stuff internal to stdlib.pas *)
 procedure getdirslot(volumeid:integer;slotNo:integer;var result:DirectorySlot;var error:integer);
 	external;
 procedure openfile(volid:integer; slotno:integer; var dirslot:DirectorySlot; var aFile:File; mode:filemode);
 	external;
 function openvolume:integer;
 var volid:integer;
 begin
 	openvolume := -1;
 	volid := findvolume(DefaultVolume);
 	if volid < 1 then
 		writeln('Volume ', DefaultVolume, ' not found.')
 	else
 		openvolume := volid;
 end;
 procedure waitForKey;
 var c:char;
 begin
 	writeln;
 	writeln('-- press any key to continue --');
 	c := conin;
 end;
 procedure copyfile(volid:integer;slotno:integer;oldname,newname:string);
 var srcfile,destfile:file;
    dirslot:DirectorySlot;
    error:integer;
    ch:char;
    count:integer;
 begin
 	(* to open the deleted source file, we emulate parts
 		of the open procedure from stdlib *)
 	getdirslot(volid, slotno, dirslot, error);
 	if not (SlotDeleted in dirslot.flags)  or (dirslot.name <> oldname) then
 		writeln('Invalid slot ', slotno)
 	else
 	begin
 		openfile(volid, slotno, dirslot, srcfile, ModeReadOnly);
 		if error <> 0 then
 			writeln('Error opening file from slot ', slotno,
 				': ', ErrorStr(error))
 		else
 		begin
 			open(destfile, newname, ModeCreate);
 			if IOResult(destfile) = IOFileExists then
 			begin
 				write('File ', newname, ' already exists, overwrite? [y/n] ');
 				readln(ch);
 				if ch in ['Y', 'y'] then
 					open(destfile, newname, ModeOverwrite);
 			end;
 			if IOResult(destfile) <> 0 then
 				writeln('Error opening ', newname, ': ',
 					ErrorStr(IOResult(destfile)))
 			else
 			begin
 				(* taken from shell.pas copyFile *)
 				write('Recovering from slot ', slotno, ' to ', newname, '...');
 				count := 0;
 				while not eof(srcfile) do
 				begin
 					read(srcfile,ch);
 					write(destfile,ch);
 					count := count + 1;
 					if (count and 8191) = 0 then write('.');
 				end;
 				writeln;
 				close(destfile);
 			end;
 			close(srcfile);
 		end;
 	end;
 end;
 procedure recoverfile(volid:integer;wantedname:string);
 var dirs:DirectorySlot;
    i:integer;
    lastSlot:integer;
    error:integer;
    screenW,screenH:integer;
    count:integer;
    datestr:string;
    ftime:DateTime;
    wantedslot:integer;
    newname:string;
    foundsomething:boolean;
 begin
 	writeln('Files available for recovery:');
 	foundsomething := false;
 	newname := '';
 	GetTermSize(screenW, screenH);
 	count := PageMargin;
 	lastSlot := volumeTable[volid].part.dirSize - 1;
 	openvolumeid(volid, error);
 		(* ignoring theoretically possible out-of-heap-space error *)
 	for i := 0 to lastSlot do
 	begin
 		getdirslot(volid, i, dirs, error);
 		with dirs do
 		begin
 			if (SlotFirst in flags) or (SlotDeleted in flags) then
 				if name = wantedname then
 				begin
 					ftime := GetDateTime(dirs.modTime);
 					datestr := DateStr(ftime) + ' ' + TimeStr(ftime, true);
 					write('slot ', i:4, name:34, sizeBytes:8, datestr:21, '  ');
 					if SlotFirst in flags then write('Cur');
 					if SlotExtent in flags then write('Extent');
 					if SlotReserved in flags then write('Resvd');
 					if SlotDeleted in flags then write('Del');
 					if SlotFree in flags then write('Free');
 					if SlotEndScan in flags then write('End');
 					writeln;
 					foundsomething := true;
 					count := count + 1;
 					if count >= screenH then
 					begin
 						count := PageMargin;
 						waitForKey;
 					end;
 					if SlotEndScan in flags then break;
 				end;
 		end;
 	end;
 	if foundsomething  then
 	begin
 		write('Slot no to recover> ');
 		readln(wantedslot);
 		if (wantedslot < 1) or (wantedslot >= volumeTable[volid].part.dirSize) then
 			writeln('Invalid slot number.')
 		else
 		begin
 			write('New filename> ');
 			readln(newname);
 		end;
 		if length(newname) > 0 then
 			copyfile(volid, wantedslot, wantedname, newname);
 	end;
 	closevolumeid(volid);
 end;
 begin
 	if ParamCount > 0 then
 		filename := ParamStr(1)
 	else
 	begin
 		write('Filename to recover> ');
 		readln(filename);
 	end;
 	volid := openvolume;
 	if volid > 0 then
 		recoverfile(volid, filename);
 end.
--- a/progs/shell.pas
+++ b/progs/shell.pas
@ -149,7 +149,7 @@ begin
 		count := PageMargin;
 		writeln('reading directory of ', DefaultVolume);
-		openvolumeid(volid, error);
+		openvolumeid(volid);
 		readdirfirst(volid, index, dirs, error);
 		while index > 0 do
 		begin
@ -324,7 +324,7 @@ begin
 		PExec(EDITORPROG, args, 3, error);
 	end
 	else
-		PExec1(EDITORPROG, ShellWorkFile, error);
+		PExec2(EDITORPROG, ShellWorkFile, error);
 	writeln('PExec error ', error);
 end;
@ -334,7 +334,7 @@ var filename:filenamestr;
 begin
 	requireWorkfile;
 	filename := replaceExtension(ShellWorkFile, '.s');
-	PExec1(ASMPROG, filename, error);
+	PExec2(ASMPROG, filename, error);
 	writeln('PExec error ', error);
 end;
@ -344,7 +344,7 @@ var filename:filenamestr;
 begin
 	requireWorkfile;
 	filename := replaceExtension(ShellWorkFile, '.pas');
-	PExec2(COMPILERPROG, '-S', filename, error);
+	PExec3(COMPILERPROG, '-S', filename, error);
 	writeln('PExec error ', error);
 end;
@ -354,7 +354,7 @@ var filename:filenamestr;
 begin
 	requireWorkfile;
 	filename := replaceExtension(ShellWorkFile, '.pas');
-	PExec1(COMPILERPROG, filename, error);
+	PExec2(COMPILERPROG, filename, error);
 	writeln('PExec error ', error);
 end;
@ -373,7 +373,7 @@ end;
 procedure krunch;
 var error:integer;
 begin
-	PExec1(RECLAIMPROG, DefaultVolume, error);
+	PExec2(RECLAIMPROG, DefaultVolume, error);
 	writeln('PExec error ', error);
 end;
--- a/progs/xfer.pas
+++ b/progs/xfer.pas
@ -226,7 +226,6 @@ begin
 	if not invalid then
 	begin
 		open(xferFile, filename, ModeOverwrite);
 		blockNo := 0;
 		done := false;
 		repeat
 			serReadBlock(ok);
@ -399,7 +398,7 @@ begin
 		writeln('Volume ', DefaultVolume, ' not found.')
 	else
 	begin
-		openvolumeid(volid, error);
+		openvolumeid(volid);
 		readdirfirst(volid, index, dirs, error);
 		while (index > 0) and (error = 0) do
 		begin
--- a/1
+++ b/1
@ -1 +0,0 @@
 Subproject commit 73936b4167bad01642675252e53a096d80fa6b35
--- a/tests/arraytest.pas
+++ b/tests/arraytest.pas
@ -1,8 +0,0 @@
 program arraytest;
 var arr:array[-5..5] of integer;
    var s:string[5];
 begin
 	arr[-5] := 10;
 	arr[5] := 11;
 	writeln(arr[-5], ' ', arr[5]);
 end.
--- a/tests/gototest.pas
+++ b/tests/gototest.pas
@ -1,22 +0,0 @@
 program gototest;
 var i:integer;
 label l1,l2;
 begin
 	goto l1;
 	writeln('skipped');
 	l1: writeln('goto destination 1');
 	{
 	for i := 1 to 10 do
 	begin
 		goto l2;
 	end;
 	}
 	{
 	case i of
 	1: writeln('1');
 	2: goto l2;
 	3..10: writeln('3 - 10');
 	end;
 	l2: writeln('goto destination 2');
 	}
 end.
--- a/tests/nestedtest.pas
+++ b/tests/nestedtest.pas
@ -1,49 +0,0 @@
 program NestedTest;
 var g:integer;
 procedure first;
 var f:integer;
  procedure second;
  var s:integer;
    procedure third1;
    var t1:integer;
    begin
 	    t1 := 310;
 	    s := 31;
 	    writeln('t1:', t1);
    end;
    procedure third2;
    var t2:integer;
    begin
 	    t2 := 320;
 	    s := 32;
 	    writeln('t2:', t2);
 	    if g <> 21 then
 	    begin
 	        g := 21;
 		second;
 	    end;
    end;
  begin
 	  f := 2;
 	  writeln('g:',g);
 	  third1;
 	  writeln('g:', g);
 	  third2;
 	  writeln('s:',s);
  end;
 begin
 	second;
 	writeln('f:', f);
 end;
 begin
 	g := 0;
 	first;
 	writeln('g:', g);
 end.
--- a/tests/settest2.pas
+++ b/tests/settest2.pas
@ -1,20 +0,0 @@
 program settest2;
 type weekday = (Mon,Tue,Wed,Thu,Fri,Sat,Sun);
     days = set of weekday;
 var s:days;
    d:weekday;
 begin
 	s := [Sat,Sun]; (* set literal  *)
 	d := Sun;
 	if d in [Sat,Sun] then (* array literal *)
 		writeln('weekend');
 	if d in s then
 		writeln('also weekend');
 	d := Mon;
 	s := s + [d];
 end.
--- a/tridoracpu/tridoracpu.srcs/Arty-A7-35-Master.xdc
+++ b/tridoracpu/tridoracpu.srcs/Arty-A7-35-Master.xdc
@ -8,8 +8,8 @@ set_property -dict {PACKAGE_PIN E3 IOSTANDARD LVCMOS33} [get_ports clk]
 create_clock -period 10.000 -name sys_clk_pin -waveform {0.000 5.000} -add [get_ports clk]
 ## Switches
-#set_property -dict {PACKAGE_PIN A8 IOSTANDARD LVCMOS33} [get_ports sw0]
+set_property -dict {PACKAGE_PIN A8 IOSTANDARD LVCMOS33} [get_ports sw0]
-#set_property -dict {PACKAGE_PIN C11 IOSTANDARD LVCMOS33} [get_ports sw1]
+set_property -dict {PACKAGE_PIN C11 IOSTANDARD LVCMOS33} [get_ports sw1]
 #set_property -dict { PACKAGE_PIN C10   IOSTANDARD LVCMOS33 } [get_ports { sw[2] }]; #IO_L13N_T2_MRCC_16 Sch=sw[2]
 #set_property -dict { PACKAGE_PIN A10   IOSTANDARD LVCMOS33 } [get_ports { sw[3] }]; #IO_L14P_T2_SRCC_16 Sch=sw[3]
@ -34,7 +34,7 @@ set_property -dict {PACKAGE_PIN T9 IOSTANDARD LVCMOS33} [get_ports led2]
 set_property -dict {PACKAGE_PIN T10 IOSTANDARD LVCMOS33} [get_ports led3]
 ## Buttons
-#set_property -dict {PACKAGE_PIN D9 IOSTANDARD LVCMOS33} [get_ports btn0]
+set_property -dict {PACKAGE_PIN D9 IOSTANDARD LVCMOS33} [get_ports btn0]
 #set_property -dict { PACKAGE_PIN C9    IOSTANDARD LVCMOS33 } [get_ports { btn1 }]; #IO_L11P_T1_SRCC_16 Sch=btn[1]
 #set_property -dict { PACKAGE_PIN B9    IOSTANDARD LVCMOS33 } [get_ports { btn[2] }]; #IO_L11N_T1_SRCC_16 Sch=btn[2]
 #set_property -dict { PACKAGE_PIN B8    IOSTANDARD LVCMOS33 } [get_ports { btn[3] }]; #IO_L12P_T1_MRCC_16 Sch=btn[3]
@ -70,10 +70,10 @@ set_property -dict {PACKAGE_PIN V14 IOSTANDARD LVCMOS33} [get_ports VGA_VS_O]
 #set_property -dict { PACKAGE_PIN U13   IOSTANDARD LVCMOS33 } [get_ports { jc[7] }]; #IO_L23N_T3_A02_D18_14 Sch=jc_n[4]
 ## Pmod Header JD
-set_property -dict { PACKAGE_PIN D4    IOSTANDARD LVCMOS33 } [get_ports { amp2_ain }]; #IO_L11N_T1_SRCC_35 Sch=jd[1]
+#set_property -dict { PACKAGE_PIN D4    IOSTANDARD LVCMOS33 } [get_ports { jd[0] }]; #IO_L11N_T1_SRCC_35 Sch=jd[1]
-set_property -dict { PACKAGE_PIN D3    IOSTANDARD LVCMOS33 } [get_ports { amp2_gain }]; #IO_L12N_T1_MRCC_35 Sch=jd[2]
+#set_property -dict { PACKAGE_PIN D3    IOSTANDARD LVCMOS33 } [get_ports { jd[1] }]; #IO_L12N_T1_MRCC_35 Sch=jd[2]
 #set_property -dict { PACKAGE_PIN F4    IOSTANDARD LVCMOS33 } [get_ports { jd[2] }]; #IO_L13P_T2_MRCC_35 Sch=jd[3]
-set_property -dict { PACKAGE_PIN F3    IOSTANDARD LVCMOS33 } [get_ports { amp2_shutdown_n }]; #IO_L13N_T2_MRCC_35 Sch=jd[4]
+#set_property -dict { PACKAGE_PIN F3    IOSTANDARD LVCMOS33 } [get_ports { jd[3] }]; #IO_L13N_T2_MRCC_35 Sch=jd[4]
 #set_property -dict { PACKAGE_PIN E2    IOSTANDARD LVCMOS33 } [get_ports { jd[4] }]; #IO_L14P_T2_SRCC_35 Sch=jd[7]
 #set_property -dict { PACKAGE_PIN D2    IOSTANDARD LVCMOS33 } [get_ports { jd[5] }]; #IO_L14N_T2_SRCC_35 Sch=jd[8]
 #set_property -dict { PACKAGE_PIN H2    IOSTANDARD LVCMOS33 } [get_ports { jd[6] }]; #IO_L15P_T2_DQS_35 Sch=jd[9]
@ -216,5 +216,3 @@ set_property -dict {PACKAGE_PIN C2 IOSTANDARD LVCMOS33} [get_ports rst]
 #set_property -dict { PACKAGE_PIN A15   IOSTANDARD LVCMOS33     } [get_ports { isns0v95_p }]; #IO_L8P_T1_AD10P_15 Sch=ad_p[10]
 set_property BITSTREAM.GENERAL.COMPRESS True [current_design]
 set_max_delay -from [get_pins vgafb0/display_timings_inst/o_vblank_reg/C] -to [get_pins vgafb0/vblank_xfer_reg/D] 3.000
--- a/tridoracpu/tridoracpu.srcs/cpuclk.v
+++ b/tridoracpu/tridoracpu.srcs/cpuclk.v
@ -17,9 +17,7 @@ module cpu_clkgen(
        .CLKFBOUT_PHASE(0.0),       // Phase offset in degrees of CLKFB (-360.000-360.000).
        .CLKIN1_PERIOD(10.0),       // Input clock period in ns to ps resolution (i.e. 33.333 is 30 MHz).
        // CLKOUT0_DIVIDE - CLKOUT6_DIVIDE: Divide amount for each CLKOUT (1-128)
-        // CPU Clock: 12.0 = 83.33MHz CPU Clock, 333.33MHz Memory Clock
+        .CLKOUT0_DIVIDE_F(12.0),    // Divide amount for CLKOUT0 (1.000-128.000).
        // 13.0 = 76.92MHz CPU Clock, 307.69MHz Memory Clock
        .CLKOUT0_DIVIDE_F(13.0),    // Divide amount for CLKOUT0 (1.000-128.000).
        .CLKOUT1_DIVIDE(5),
        .CLKOUT2_DIVIDE(40),        // 40 = 25MHz pixel clock (should be 25.175MHz per spec) for 640x480
        //.CLKOUT2_DIVIDE(25),        // 25 = 40MHz pixel clock for 800x600
--- a/tridoracpu/tridoracpu.srcs/dram_bridge.v
+++ b/tridoracpu/tridoracpu.srcs/dram_bridge.v
@ -8,7 +8,6 @@ module dram_bridge #(ADDR_WIDTH = 32, WIDTH = 32)
    input wire [WIDTH-1:0]      mem_write_data,
    input wire                  mem_read_enable,
    input wire                  mem_write_enable,
    input wire                  mem_read_ins,
    output wire                 mem_wait,
    input wire                  rst_n,
@ -106,57 +105,39 @@ module dram_bridge #(ADDR_WIDTH = 32, WIDTH = 32)
       .sys_rst                        (rst_n)
    );
-    (*KEEP*) reg [DRAM_DATA_WIDTH-1:0] 	ins_cache;
+//    reg [DRAM_DATA_WIDTH-1:0] 	read_cache;
-    (*KEEP*) reg [DRAM_ADDR_WIDTH-1:4]  icached_addr;
+//    reg [ADDR_WIDTH-1:0]      	cached_addr;
-    (*KEEP*) wire                       icache_hit = mem_read_enable && mem_read_ins && (icached_addr == mem_addr[DRAM_ADDR_WIDTH-1:4]);
+//    wire 		      	cache_hit = cached_addr == mem_addr;
-
+//    wire [DRAM_DATA_WIDTH-1:0]  read_data_wrapper = cache_hit ? read_cache : app_rd_data;
    (*KEEP*) reg [DRAM_DATA_WIDTH-1:0] 	d_cache;
    (*KEEP*) reg [DRAM_ADDR_WIDTH-1:4]  dcached_addr;
    (*KEEP*) wire                       dcache_hit = mem_read_enable && !mem_read_ins && (dcached_addr == mem_addr[DRAM_ADDR_WIDTH-1:4]);
    wire cache_hit = icache_hit | dcache_hit;
    reg [WIDTH-1:0] read_buf;
    reg read_inprogress = 0;
    wire dram_read_enable = mem_read_enable && !cache_hit;
    assign app_rd_data_end = 1'b1;
    //assign app_wdf_mask = 16'b1111111111111100;
    // addresses on the memory interface are aligned to 16 bytes
    // and 28 bits wide (=256MB)
    assign app_addr = { mem_addr[DRAM_ADDR_WIDTH:4], 4'b0000 };
    //assign app_addr = { 28'b0 };
    // select a word from the 128 bits transferred by the dram controller
    // according to the lower bits of the address (ignoring bits 1:0)
    wire [WIDTH-1:0] read_word;
    wire [1:0] word_sel = mem_addr[3:2];
-    wire [WIDTH-1:0] read_word =
+    assign read_word =  word_sel == 3'b11 ? app_rd_data[31:0]  :
-                        word_sel == 2'b11 ? app_rd_data[31:0]  :
+                        word_sel == 3'b10 ? app_rd_data[63:32] :
-                        word_sel == 2'b10 ? app_rd_data[63:32] :
+                        word_sel == 3'b01 ? app_rd_data[95:64] :
                        word_sel == 2'b01 ? app_rd_data[95:64] :
                                            app_rd_data[127:96];
-    wire [WIDTH-1:0] read_icached_word =
+    assign mem_read_data = app_rd_data_valid ? read_word : read_buf;
                        word_sel == 2'b11 ? ins_cache[31:0]  :
                        word_sel == 2'b10 ? ins_cache[63:32] :
                        word_sel == 2'b01 ? ins_cache[95:64] :
                                            ins_cache[127:96];
    wire [WIDTH-1:0] read_dcached_word =
                        word_sel == 2'b11 ? d_cache[31:0]  :
                        word_sel == 2'b10 ? d_cache[63:32] :
                        word_sel == 2'b01 ? d_cache[95:64] :
                                            d_cache[127:96];
    (*KEEP*) assign mem_read_data = icache_hit ? read_icached_word :
                            dcache_hit ? read_dcached_word :
                            app_rd_data_valid ? read_word : read_buf;
    // set the write mask according to the lower bits of the address
    // (ignoring bit 0)
-    assign app_wdf_mask = word_sel == 2'b11 ? 16'b1111111111110000 :
+    assign app_wdf_mask = word_sel == 3'b11 ? 16'b1111111111110000 :
-                          word_sel == 2'b10 ? 16'b1111111100001111 :
+                          word_sel == 3'b10 ? 16'b1111111100001111 :
-                          word_sel == 2'b01 ? 16'b1111000011111111 :
+                          word_sel == 3'b01 ? 16'b1111000011111111 :
                                              16'b0000111111111111 ;
    wire write_ready = mem_write_enable & app_wdf_rdy & app_rdy;
@ -164,67 +145,21 @@ module dram_bridge #(ADDR_WIDTH = 32, WIDTH = 32)
    assign app_wdf_end =  mem_write_enable & write_ready;
    assign app_wdf_data = { {4{mem_write_data}} };
-    assign mem_wait =   (dram_read_enable & ~read_inprogress) |
+    assign mem_wait =   (mem_read_enable & ~read_inprogress) |
                        (mem_write_enable & (~app_wdf_rdy | ~app_rdy)) |
                        (read_inprogress & ~app_rd_data_valid);
-    assign app_en = (dram_read_enable & ~read_inprogress) |
+    assign app_en = (mem_read_enable & ~read_inprogress) |
            (mem_write_enable & write_ready);
-    assign app_cmd = dram_read_enable ? CMD_READ : CMD_WRITE;
+    assign app_cmd = mem_read_enable ? CMD_READ : CMD_WRITE;
    /* set instruction cache */
    always @(posedge dram_front_clk)
    begin
-        if(dram_read_enable && mem_read_ins && app_rd_data_valid)
+        if(mem_read_enable & ~read_inprogress & app_rdy)
        begin
            ins_cache <= app_rd_data;
            icached_addr <= mem_addr[DRAM_ADDR_WIDTH-1:4];
        end
    end
    /* set data cache */
    always @(posedge dram_front_clk)
    begin
        if(dram_read_enable && !mem_read_ins && app_rd_data_valid)
        begin
            d_cache <= app_rd_data;
            dcached_addr <= mem_addr[DRAM_ADDR_WIDTH-1:4];
        end
        /* write-through cache - invalidate on write */
        /* invalidate data cache on write */
 //         if(mem_write_enable && dcached_addr == mem_addr[DRAM_ADDR_WIDTH-1:4])
 //            dcached_addr <= {DRAM_ADDR_WIDTH-4{1'b1}};
        /* write-back cache - update cache on write */
        // write back to data cache on mem_write
        if(mem_write_enable && dcached_addr == mem_addr[DRAM_ADDR_WIDTH-1:4])
        begin
            case(word_sel)
                2'b11: d_cache[31:0] <= mem_write_data;
                2'b10: d_cache[63:32] <= mem_write_data;
                2'b01: d_cache[95:64] <= mem_write_data;
                2'b00: d_cache[127:96] <= mem_write_data;
            endcase            
        end
    end
    /* transfer read data, either from cache or from DRAM */
    always @(posedge dram_front_clk)
    begin
        if(dram_read_enable & ~read_inprogress & app_rdy)
            read_inprogress <= 1;
        if(read_inprogress & app_rd_data_valid)
            read_inprogress <= 0;
-
+        if(mem_read_enable & app_rd_data_valid)
        if(dram_read_enable & app_rd_data_valid)
            read_buf <= mem_read_data;
        else
        if (mem_read_enable & icache_hit)
            read_buf <= read_icached_word;
        else
        if (mem_read_enable & dcache_hit)
            read_buf <= read_dcached_word;
    end
 endmodule
--- a/tridoracpu/tridoracpu.srcs/irqctrl.v
+++ b/tridoracpu/tridoracpu.srcs/irqctrl.v
@ -1,6 +1,6 @@
 `timescale 1ns / 1ps
-module irqctrl #(IRQ_LINES = 3, IRQ_DELAY_WIDTH = 8) (
+module irqctrl #(IRQ_LINES = 2, IRQ_DELAY_WIDTH = 4) (
        input wire clk,
        input wire [IRQ_LINES-1:0] irq_in,
        input wire cs,
--- a/tridoracpu/tridoracpu.srcs/mem.v
+++ b/tridoracpu/tridoracpu.srcs/mem.v
@ -28,7 +28,7 @@ module rom32 #(parameter ADDR_WIDTH = 11, DATA_WIDTH = 32)
    input wire read_enable
    );
-  wire [ADDR_WIDTH-2:0] internal_addr = addr[ADDR_WIDTH-1:2];   // -> ignore bits 1-0
+  wire [ADDR_WIDTH-2:0] internal_addr = addr[ADDR_WIDTH-1:2];   // -> ignore bit 0
  reg [DATA_WIDTH-1:0] rom [0:(2**(ADDR_WIDTH-2))-1];
  initial begin
@ -51,7 +51,7 @@ module ram32 #(parameter ADDR_WIDTH = 16, DATA_WIDTH = 32)
    );
  reg [DATA_WIDTH-1:0] ram [0:(2**(ADDR_WIDTH-2))-1];           // 32bit words with byte addressing
-  wire [ADDR_WIDTH-2:0] internal_addr = addr[ADDR_WIDTH-1:2];   // -> ignore bits 1-0
+  wire [ADDR_WIDTH-2:0] internal_addr = addr[ADDR_WIDTH-1:2];   // -> ignore bit 1-0
  always @(posedge clk)
  begin
@ -91,10 +91,8 @@ module mem #(parameter ADDR_WIDTH = 32,
  // RAM1 $1000 - $FFFF 60K
  // RAM2 $10000 - $FFFFFFFF ~4GB
  localparam RAM1_ADDR_WIDTH = 16;
  wire ram_cs = addr[ADDR_WIDTH-1:12] != { {(ADDR_WIDTH-12){1'b0}}};
-  wire ram1_cs = ram_cs && (addr[ADDR_WIDTH-1:RAM1_ADDR_WIDTH] == { {(ADDR_WIDTH-RAM1_ADDR_WIDTH){1'b0}}});
+  wire ram1_cs = ram_cs && (addr[ADDR_WIDTH-1:16] == { {(ADDR_WIDTH-16){1'b0}}});
  wire ram2_cs = ram_cs && !ram1_cs;
  wire rom_cs = !ram_cs && addr[11] == 1'b0;
  wire io_cs = !ram_cs && addr[11]  == 1'b1;
@ -118,10 +116,10 @@ module mem #(parameter ADDR_WIDTH = 32,
  // test
  reg [1:0] wait_state;
-  ram32 #(.ADDR_WIDTH(RAM1_ADDR_WIDTH)) ram0  // 64KB RAM
+  ram32 #(.ADDR_WIDTH(16)) ram0  // 64KB RAM
  (
    .clk(clk),
-    .addr(addr[RAM1_ADDR_WIDTH-1:0]),
+    .addr(addr[15:0]),
    .data_out(ram_out),
    .read_enable(ram_read),
    .data_in(data_in),
--- a/tridoracpu/tridoracpu.srcs/mig_dram_0/mig_a.prj
+++ b/tridoracpu/tridoracpu.srcs/mig_dram_0/mig_a.prj
@ -39,12 +39,12 @@
  <Controller number="0">
    <MemoryDevice>DDR3_SDRAM/Components/MT41K128M16XX-15E</MemoryDevice>
-    <TimePeriod>3300</TimePeriod>
+    <TimePeriod>3000</TimePeriod>
    <VccAuxIO>1.8V</VccAuxIO>
    <PHYRatio>4:1</PHYRatio>
-    <InputClkFreq>75.757</InputClkFreq>
+    <InputClkFreq>83.333</InputClkFreq>
    <UIExtraClocks>0</UIExtraClocks>
-    <MMCM_VCO>606</MMCM_VCO>
+    <MMCM_VCO>666</MMCM_VCO>
    <MMCMClkOut0> 1.000</MMCMClkOut0>
    <MMCMClkOut1>1</MMCMClkOut1>
    <MMCMClkOut2>1</MMCMClkOut2>
--- a/tridoracpu/tridoracpu.srcs/mig_dram_0/mig_b.prj
+++ b/tridoracpu/tridoracpu.srcs/mig_dram_0/mig_b.prj
@ -39,12 +39,12 @@
  <Controller number="0">
    <MemoryDevice>DDR3_SDRAM/Components/MT41K128M16XX-15E</MemoryDevice>
-    <TimePeriod>3250</TimePeriod>
+    <TimePeriod>3000</TimePeriod>
    <VccAuxIO>1.8V</VccAuxIO>
    <PHYRatio>4:1</PHYRatio>
-    <InputClkFreq>76.923</InputClkFreq>
+    <InputClkFreq>83.333</InputClkFreq>
    <UIExtraClocks>0</UIExtraClocks>
-    <MMCM_VCO>615</MMCM_VCO>
+    <MMCM_VCO>666</MMCM_VCO>
    <MMCMClkOut0> 1.000</MMCMClkOut0>
    <MMCMClkOut1>1</MMCMClkOut1>
    <MMCMClkOut2>1</MMCMClkOut2>
--- a/tridoracpu/tridoracpu.srcs/mig_dram_0/mig_dram_0.xci
+++ b/tridoracpu/tridoracpu.srcs/mig_dram_0/mig_dram_0.xci
--- a/tridoracpu/tridoracpu.srcs/sdspi.v
+++ b/tridoracpu/tridoracpu.srcs/sdspi.v
@ -107,7 +107,7 @@ module sdspi(
        tx_fifo_empty
    );
-    fifo #(.ADDR_WIDTH(10)) rx_fifo(clk, reset,
+    fifo #(.ADDR_WIDTH(8)) rx_fifo(clk, reset,
        rx_fifo_wr_en, rx_fifo_rd_en,
        rx_shifter, rx_fifo_out,
        rx_fifo_full,
--- a/tridoracpu/tridoracpu.srcs/stackcpu.v
+++ b/tridoracpu/tridoracpu.srcs/stackcpu.v
@ -11,14 +11,20 @@ module stackcpu #(parameter ADDR_WIDTH = 32, WIDTH = 32,
    output reg [ADDR_WIDTH-1:0] addr,
    input wire [WIDTH-1:0] data_in,
    output wire read_enable,
    output wire read_ins,
    output wire [WIDTH-1:0] data_out,
    output wire write_enable,
    input wire mem_wait,
-    output wire debug1,
+    output wire led1,
-    output wire debug2,
+    output wire led2,
-    output wire debug3
+    output wire led3,
    output wire [WIDTH-1:0] debug_out1,
    output wire [WIDTH-1:0] debug_out2,
    output wire [WIDTH-1:0] debug_out3,
    output wire [WIDTH-1:0] debug_out4,
    output wire [WIDTH-1:0] debug_out5,
    output wire [WIDTH-1:0] debug_out6
    );
    localparam EVAL_STACK_INDEX_WIDTH = 6;
@ -90,6 +96,7 @@ module stackcpu #(parameter ADDR_WIDTH = 32, WIDTH = 32,
    wire mem_write;
    wire x_is_zero;
    // wire [WIDTH-1:0] y_plus_operand = Y + operand;
    wire x_equals_y = X == Y;
    wire y_lessthan_x  = $signed(Y) < $signed(X);
@ -104,10 +111,16 @@ module stackcpu #(parameter ADDR_WIDTH = 32, WIDTH = 32,
    assign write_enable = mem_write_enable;
    // debug output ------------------------------------------------------------------------------------
-    assign debug1 = reset;
+    assign led1 = reset;
-    assign debug2 = ins_loadc;
+    assign led2 = ins_loadc;
-    assign debug3 = ins_branch;
+    assign led3 = ins_branch;
-
+//    assign debug_out1 = { mem_read_enable, mem_write_enable, x_is_zero,
 //                    ins_branch, ins_aluop, y_lessthan_x, x_equals_y, {7{1'b0}}, seq_state};
 //    assign debug_out2 = data_in;
 //    assign debug_out3 = nX;
 //    assign debug_out4 = nPC;
 //    assign debug_out5 = ins;
 //    assign debug_out6 = IV;
    //--------------------------------------------------------------------------------------------------
    // instruction decoding
@ -169,8 +182,6 @@ module stackcpu #(parameter ADDR_WIDTH = 32, WIDTH = 32,
    assign mem_read_enable  = (seq_state == FETCH) || (seq_state == EXEC && mem_read);
    assign mem_write_enable = (seq_state == MEM && mem_write);
    assign read_ins = (seq_state == FETCH) || (seq_state == DECODE);
    initial
    begin
        PC <= 0; nPC <= 0; seq_state <= MEM;
@ -399,10 +410,7 @@ module stackcpu #(parameter ADDR_WIDTH = 32, WIDTH = 32,
    // process irq
    always @(posedge clk)
    begin
-        // in MEM state, clear irq_pending, when nPC has been set to IV
+        if(seq_state == MEM && irq_pending && !(ins_xfer & xfer_r2p))   // in FETCH state, clear irq_pending.
        // RET instruction is a special case because we need to use
        // the new PC that is in mem_data
        if(seq_state == MEM && irq_pending && !(ins_xfer && xfer_r2p))
            irq_pending <= 0;
        else
            irq_pending <= irq_pending || irq;  // else set irq_pending when irq is high
--- a/tridoracpu/tridoracpu.srcs/tdraudio.v
+++ b/tridoracpu/tridoracpu.srcs/tdraudio.v
@ -1,270 +0,0 @@
 `timescale 1ns / 1ps
 // waveform generator module (PCM)
 module wavegen #(DATA_WIDTH=32, CLOCK_DIV_WIDTH=22,
    AMP_WIDTH=16, AMP_BIAS=32768) (
        input wire clk,
        input wire reset,
        input wire [1:0] reg_sel,
        output wire [DATA_WIDTH-1:0] rd_data,
        input wire [AMP_WIDTH-1:0] wr_data,
        input wire rd_en,
        input wire wr_en,
        output wire [AMP_WIDTH-1:0] amp_val,
        output wire running,
        output wire irq
    );
    localparam TDRAU_REG_CTL = 0;  /* control register */
    localparam TDRAU_REG_CLK = 1;  /* clock divider register */
    localparam TDRAU_REG_AMP = 2;  /* amplitude (volume) register */
     /* avoid warning about unconnected port */
    (* keep="soft" *) wire _unused = rd_en;
    reg channel_enable;
    reg [CLOCK_DIV_WIDTH-1:0] clock_div;
    reg [CLOCK_DIV_WIDTH-1:0] div_count;
    reg amp_phase;
    reg [AMP_WIDTH-1:0] amp_out;
    wire fifo_wr_en;
    wire fifo_rd_en, fifo_full, fifo_empty;
    wire [AMP_WIDTH-1:0] fifo_rd_data;
    fifo #(.ADDR_WIDTH(4), .DATA_WIDTH(16)) sample_buf(
        clk, reset,
        fifo_wr_en, fifo_rd_en,
        wr_data[AMP_WIDTH-1:0], fifo_rd_data,
        fifo_full,
        fifo_empty
    );
    assign fifo_rd_en = (div_count == 0) && channel_enable && ~fifo_empty;
    assign fifo_wr_en = wr_en && (reg_sel == TDRAU_REG_AMP);
    reg irq_buf, irq_enable;
    assign irq = channel_enable && irq_buf;
    reg [DATA_WIDTH-1:0] rd_data_buf;
    assign rd_data = rd_data_buf;
    assign amp_val = amp_out;
    assign running = channel_enable;
    wire ctl_reg_write = wr_en && (reg_sel == TDRAU_REG_CTL);
    /* update read data buffer */
    always @(posedge clk)
    begin
        rd_data_buf <= {{DATA_WIDTH-8{1'b0}},
            {3{1'b0}}, irq_enable, fifo_full, fifo_empty, amp_phase, channel_enable};
    end
    /* irq signal to interrupt controller */
    always @(posedge clk)
    begin
        if(reset)
            irq_buf <= 0;
        else
        if(fifo_empty && irq_enable)
            irq_buf <= 1;
        else
            irq_buf <= 0;
    end
    /* interrupt enable flag  */
    always @(posedge clk)
    begin
        if(reset)
            irq_enable <= 0;
        else
        if(ctl_reg_write)
            irq_enable <= wr_data[4];
        else
        if(irq_buf)
            irq_enable <= 0;  // disable interrupts after an interrupt
    end
    /* channel enable flag */
    always @(posedge clk)
    begin
        if(reset)
            channel_enable <= 0;
        else if (ctl_reg_write)
            channel_enable <= wr_data[0];
    end
    /* clock divider register */
    always @(posedge clk)
    begin
        if(reset)
            clock_div <= 0;
        else
        if (wr_en && (reg_sel == TDRAU_REG_CLK))
             clock_div <= wr_data;
    end
    /* divider counter */
    always @(posedge clk)
    begin
        if(channel_enable)
        begin
            if(div_count == 0)      // reset counter if it reaches zero
                div_count <= clock_div;
            else
                div_count <= div_count - 1;  // else just decrement it
        end
        else
        if (wr_en && (reg_sel == TDRAU_REG_CLK)) // when setting divider,
                div_count <= 1; // start cycle on next clock tick
    end
    /* amplitude out */
    always @(posedge clk)
    begin
        if (reset)
        begin
            amp_out <= AMP_BIAS;
            amp_phase <= 1;
        end
        else
        if (channel_enable)
        begin
            if (div_count == 0) // invert amplitude on clock tick
            begin
                amp_out <=  fifo_rd_data;
                amp_phase <= ~amp_phase;
            end
        end
        else
            amp_out <= AMP_BIAS;
        // reset phase bit when enabling the channel
        if (ctl_reg_write && wr_data[0] && ~channel_enable)
            // when channel is being enabled, phase will be flipped on next tick
            // because div_count will become zero
            amp_phase <= 1;
    end
 endmodule
 module tdraudio #(DATA_WIDTH=32) (
        input wire clk,
        input wire reset,
        input wire [6:0] io_addr,
        output wire [DATA_WIDTH-1:0] rd_data,
        input wire [DATA_WIDTH-1:0] wr_data,
        input wire rd_en,
        input wire wr_en,
        output wire irq_out,
        output wire pdm_out,
        output wire gain_sel,
        output wire shutdown_n
    );
    localparam CLOCK_DIV_WIDTH = 22;
    localparam AMP_WIDTH = 16;
    localparam AMP_BIAS = 32768;
    localparam DAC_WIDTH = 18;
     /* avoid warning about unconnected port */
    (* keep="soft" *) wire [DATA_WIDTH-1:AMP_WIDTH] _unused = wr_data[DATA_WIDTH-1:AMP_WIDTH];
    wire [4:0] chan_sel = io_addr[6:2];
    wire [1:0] reg_sel = io_addr[1:0];
    wire [AMP_WIDTH-1:0] amp_wr_data = wr_data[AMP_WIDTH-1:0];
    wire [AMP_WIDTH-1:0] chan0_amp;
    wire [DATA_WIDTH-1:0] chan0_rd_data;
    wire chan0_running;
    wire chan0_irq;
    wire chan0_sel = chan_sel == 5'd0;
    wire chan0_rd_en = chan0_sel && rd_en;
    wire chan0_wr_en = chan0_sel && wr_en;
    wire [AMP_WIDTH-1:0] chan1_amp;
    wire [DATA_WIDTH-1:0] chan1_rd_data;
    wire chan1_running;
    wire chan1_irq;
    wire chan1_sel = chan_sel == 5'd1;
    wire chan1_rd_en = chan1_sel && rd_en;
    wire chan1_wr_en = chan1_sel && wr_en;
    wire [AMP_WIDTH-1:0] chan2_amp;
    wire [DATA_WIDTH-1:0] chan2_rd_data;
    wire chan2_running;
    wire chan2_irq;
    wire chan2_sel = chan_sel == 5'd2;
    wire chan2_rd_en = chan2_sel && rd_en;
    wire chan2_wr_en = chan2_sel && wr_en;
    wire [AMP_WIDTH-1:0] chan3_amp;
    wire [DATA_WIDTH-1:0] chan3_rd_data;
    wire chan3_running;
    wire chan3_irq;
    wire chan3_sel = chan_sel == 5'd3;
    wire chan3_rd_en = chan3_sel && rd_en;
    wire chan3_wr_en = chan3_sel && wr_en;
    wire running = chan0_running || chan1_running || chan2_running || chan3_running;
    assign rd_data = chan0_sel ? chan0_rd_data :
                        chan1_sel ? chan1_rd_data :
                        chan2_sel ? chan2_rd_data :
                        chan3_sel ? chan3_rd_data :
                        {DATA_WIDTH{1'b1}};
    wavegen chan0(clk, reset, reg_sel,
        chan0_rd_data, amp_wr_data,
        chan0_rd_en, chan0_wr_en,
        chan0_amp,
        chan0_running, chan0_irq);
    wavegen chan1(clk, reset, reg_sel,
        chan1_rd_data, amp_wr_data,
        chan1_rd_en, chan1_wr_en,
        chan1_amp,
        chan1_running, chan1_irq);
    wavegen chan2(clk, reset, reg_sel,
        chan2_rd_data, amp_wr_data,
        chan2_rd_en, chan2_wr_en,
        chan2_amp,
        chan2_running, chan2_irq);
    wavegen chan3(clk, reset, reg_sel,
        chan3_rd_data, amp_wr_data,
        chan3_rd_en, chan3_wr_en,
        chan3_amp,
        chan3_running, chan3_irq);
    reg [DAC_WIDTH:0] deltasigma_acc; // one extra bit
    wire [DAC_WIDTH:0] amp_sum = chan0_amp + chan1_amp + chan2_amp + chan3_amp; // also one overflow bit here
    assign gain_sel = 1;  // gain select: 0 -> 12dB, 1 -> 6dB
    // assign shutdown_n = running;
    assign shutdown_n = 1;  /* don't enable shutdown mode, it creates a mains hum */
    reg irq_out_buf;
    assign irq_out = irq_out_buf;
    always @(posedge clk) irq_out_buf <= chan0_irq || chan1_irq || chan2_irq || chan3_irq;
    /* delta-sigma DAC */
    always @(posedge clk)
    begin
        if(reset)
            deltasigma_acc <= 0;
        else
 //        if (running)
            deltasigma_acc <= deltasigma_acc[DAC_WIDTH-1:0] + amp_sum;
 //        else
 //            deltasigma_acc <= deltasigma_acc[DAC_WIDTH-1:0] + (4*AMP_BIAS);
    end
    /* 1-bit audio output */
    assign pdm_out = deltasigma_acc[DAC_WIDTH];
 endmodule
--- a/tridoracpu/tridoracpu.srcs/top.v
+++ b/tridoracpu/tridoracpu.srcs/top.v
@ -3,18 +3,19 @@
 // or as clk_1hz for debugging
 `define clock cpuclk
-//`define clkfreq 83333333
+`define clkfreq 83333333
 `define clkfreq 76923076
 //`define clock clk
 //`define clkfreq 100000000
 //`define clock clk_1hz
 `define ENABLE_VGAFB
 `define ENABLE_MICROSD
 `define ENABLE_TDRAUDIO
 module top(
    input wire clk,
    input wire rst,
    input wire btn0,
    input wire sw0,
    input wire sw1,
    output wire led0,
    output wire led1,
    output wire led2,
@ -58,13 +59,6 @@ module top(
    output wire sd_sck,
    input wire  sd_cd
 `endif
 `ifdef ENABLE_TDRAUDIO
    ,
    output wire amp2_ain,
    output wire amp2_gain,
    output wire amp2_shutdown_n
 `endif
 );
    reg clk_1hz;
@ -73,11 +67,10 @@ module top(
    localparam ADDR_WIDTH = 32, WIDTH = 32,
            ROMADDR_WIDTH = 11, IOADDR_WIDTH = 11, IOADDR_SEL = 4;
-    (* KEEP *) wire [ADDR_WIDTH-1:0] mem_addr;
+    wire [ADDR_WIDTH-1:0] mem_addr;
    wire [WIDTH-1:0] mem_read_data;
    wire [WIDTH-1:0] mem_write_data;
    (* KEEP *) wire mem_wait;
    assign led0 = mem_wait;
    (* KEEP *) wire mem_read_enable;
    (* KEEP *) wire mem_write_enable;
@ -87,6 +80,14 @@ module top(
    wire irq;
    // assign led0 = mem_wait;
    wire [WIDTH-1:0] debug_data1, debug_data2,
        debug_data3, debug_data4,
        debug_data5, debug_data6;
    assign led0 = debug_data6[0];
    wire cpuclk, cpuclk_locked;
    wire dram_refclk200;
    wire pixclk;
@ -96,11 +97,9 @@ module top(
    wire [ADDR_WIDTH-1:0] dram_addr;
    wire [WIDTH-1:0] dram_read_data, dram_write_data;
    wire dram_read_enable, dram_write_enable, dram_wait;
    (* KEEP *) wire dram_read_ins;
    dram_bridge dram_bridge0 (dram_addr,
-        dram_read_data, dram_write_data, dram_read_enable, dram_write_enable,
+        dram_read_data, dram_write_data, dram_read_enable, dram_write_enable, dram_wait,
        dram_read_ins, dram_wait,
        rst, cpuclk, dram_refclk200,
        ddr3_dq, ddr3_dqs_n, ddr3_dqs_p, ddr3_addr,
        ddr3_ba, ddr3_ras_n, ddr3_cas_n, ddr3_we_n,
@ -137,7 +136,7 @@ module top(
    assign fb_wr_data = mem_write_data;
    vgafb vgafb0(`clock, pixclk, rst,
-        mem_addr[5:2], fb_rd_data, fb_wr_data,
+        mem_addr[3:0], fb_rd_data, fb_wr_data,
        fb_rd_en, fb_wr_en,
        VGA_HS_O, VGA_VS_O, VGA_R, VGA_G, VGA_B);
 `endif
@ -225,44 +224,11 @@ module top(
    assign uart_tx_data = mem_write_data[7:0];
    assign uart_rd_data = { {WIDTH-10{1'b1}}, uart_rx_avail, uart_tx_busy, uart_rx_data };
    wire audio_irq;
    buart #(.CLKFREQ(`clkfreq)) uart0(`clock, rst,
        uart_baud,
        uart_txd_in, uart_rxd_out,
        uart_rx_clear, uart_tx_en,
        uart_rx_avail, uart_tx_busy,
        uart_tx_data, uart_rx_data);
    // audio controller
 `ifdef ENABLE_TDRAUDIO
    wire [WIDTH-1:0] tdraudio_wr_data;
    wire [WIDTH-1:0] tdraudio_rd_data;
    wire tdraudio_rd_en, tdraudio_wr_en;
    wire tdraudio_irq;
    wire tdraudio_cs_en = io_enable && (io_slot == 4);
    assign tdraudio_rd_en = tdraudio_cs_en && mem_read_enable;
    assign tdraudio_wr_en = tdraudio_cs_en && mem_write_enable;
    assign tdraudio_wr_data = mem_write_data;
    tdraudio tdraudio0(`clock, ~rst,
        mem_addr[8:2],
        tdraudio_rd_data,
        tdraudio_wr_data,
        tdraudio_rd_en,
        tdraudio_wr_en,
        tdraudio_irq,
        amp2_ain, amp2_gain, amp2_shutdown_n);
    assign audio_irq = tdraudio_irq;
 `endif
    // interrupt controller
    reg timer_tick;
    reg[23:0] tick_count;
-    wire [2:0] irq_in = { audio_irq, timer_tick, uart_rx_avail };
+    wire [1:0] irq_in = { timer_tick, uart_rx_avail };
-    wire [2:0] irqc_rd_data0;
+    wire [1:0] irqc_rd_data0;
-    wire [WIDTH-1:0] irqc_rd_data = { tick_count, 5'b0, irqc_rd_data0 };
+    wire [WIDTH-1:0] irqc_rd_data = { tick_count, 6'b0, irqc_rd_data0 };
    wire irqc_seten = mem_write_data[7];
    wire irqc_cs = io_enable && (io_slot == 3);
@ -274,23 +240,34 @@ module top(
                        (io_slot == 2) ? fb_rd_data :
    `endif
                        (io_slot == 3) ? irqc_rd_data:
-    `ifdef ENABLE_TDRAUDIO
+
                        (io_slot == 4) ? tdraudio_rd_data:
    `endif
                        -1;
-    irqctrl irqctrl0(`clock, irq_in, irqc_cs, mem_write_enable,
+
-            irqc_seten, irqc_rd_data0,
+    buart #(.CLKFREQ(`clkfreq)) uart0(`clock, rst,
-            irq);
+        uart_baud,
        uart_txd_in, uart_rxd_out,
        uart_rx_clear, uart_tx_en,
        uart_rx_avail, uart_tx_busy,
        uart_tx_data, uart_rx_data);
     // CPU -----------------------------------------------------------------
    stackcpu cpu0(.clk(`clock), .rst(rst), .irq(irq),
        .addr(mem_addr),
        .data_in(mem_read_data), .read_enable(mem_read_enable),
        .read_ins(dram_read_ins),
        .data_out(mem_write_data), .write_enable(mem_write_enable),
        .mem_wait(mem_wait),
-        .debug1(led1), .debug2(led2), .debug3(led3));
+        .led1(led1), .led2(led2), .led3(led3),
        .debug_out1(debug_data1),
        .debug_out2(debug_data2),
        .debug_out3(debug_data3),
        .debug_out4(debug_data4),
        .debug_out5(debug_data5),
        .debug_out6(debug_data6));
    // Interrupt Controller
    irqctrl irqctrl0(`clock, irq_in, irqc_cs, mem_write_enable,
            irqc_seten, irqc_rd_data0,
            irq);
    // count clock ticks
    // generate interrupt every 20nth of a second
--- a/tridoracpu/tridoracpu.srcs/vgafb.v
+++ b/tridoracpu/tridoracpu.srcs/vgafb.v
@ -1,19 +1,13 @@
 `timescale 1ns / 1ps
 `default_nettype none
 // enable shifter/masker registers
 `define ENABLE_FB_ACCEL
 // Project F: Display Timings
 // (C)2019 Will Green, Open Source Hardware released under the MIT License
 // Learn more at https://projectf.io
 //128K video memory is not enough for 640x480x4
-//`define RES_640_400
+`define RES_640_400
 //`define RES_1024_768
 // RES_640_480 mode displays 400 lines with 640x480/60 video timings,
 // adding blank lines at the bottom
 `define RES_640_480
 module display_timings #(
    H_RES=640,                      // horizontal resolution (pixels)
@ -68,11 +62,10 @@ module display_timings #(
    // o_scanline: high for one tick at the start of each visible scanline
    assign o_scanline = (o_sy >= VA_STA) && (o_sy <= VA_END) && (o_sx == H_STA);
    // set vblank at end of frame, clear at start
    always @(posedge i_pix_clk)
    begin
-        if(o_sy == VA_END) o_vblank <= 1;
+        if(o_frame) o_vblank <= 1;
-        else if (o_sy == -1) o_vblank <= 0;
+        else if (o_de) o_vblank <= 0;
    end
    always @ (posedge i_pix_clk)
@ -129,19 +122,9 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
    localparam REG_PAL_SLOT = 3; localparam REG_PAL_DATA = 4;
    localparam REG_CTL = 5;
 `ifdef ENABLE_FB_ACCEL
    localparam REG_SHIFTER = 6;
    localparam REG_SHIFTCOUNT = 7;
    localparam REG_SHIFTERM = 8;
    localparam REG_SHIFTERSP = 09;
    localparam REG_MASKGEN = 10;
 `endif
    localparam COLOR_WIDTH = 12;
    localparam PALETTE_WIDTH = 4;
    localparam signed PIC_LINES = 400; // visible picture lines
    // Display Clocks
    wire pix_clk = CLK;                   // pixel clock
    wire clk_lock = 1;                  // clock locked?
@ -156,32 +139,12 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
    wire pix_rd;
    wire [VMEM_DATA_WIDTH-1:0] status;
 `ifdef ENABLE_FB_ACCEL
    reg [VMEM_DATA_WIDTH-1:0] acc_shifter_in;
    reg [(VMEM_DATA_WIDTH*2)-1:0] acc_shifter_out;
    reg [4:0] acc_shift_count;
    reg acc_start_shift;
    reg [VMEM_DATA_WIDTH-1:0] acc_mask_in;
    reg [VMEM_DATA_WIDTH-1:0] acc_mask_buf;
    reg [VMEM_DATA_WIDTH-1:0] acc_shiftmask_buf;
    wire [VMEM_DATA_WIDTH-1:0] acc_shifter_mask = acc_shiftmask_buf;
    wire [VMEM_DATA_WIDTH-1:0] acc_shifter_out_h = acc_shifter_out[(VMEM_DATA_WIDTH*2)-1:VMEM_DATA_WIDTH];
    wire [VMEM_DATA_WIDTH-1:0] acc_shifter_out_l = acc_shifter_out[VMEM_DATA_WIDTH-1:0];
 `endif
    assign vmem_rd_en = rd_en;
    assign vmem_wr_en = (reg_sel == REG_VMEM) && wr_en;
    assign rd_data = (reg_sel == REG_VMEM)      ? vmem_rd_data :
                     (reg_sel == REG_RD_ADDR)   ? cpu_rd_addr :
                     (reg_sel == REG_WR_ADDR)   ? cpu_wr_addr :
                     (reg_sel == REG_CTL)       ? status :
 `ifdef ENABLE_FB_ACCEL
                     (reg_sel == REG_SHIFTER)   ? acc_shifter_out_h:
                     (reg_sel == REG_SHIFTERM)  ? acc_shiftmask_buf :
                     (reg_sel == REG_SHIFTERSP) ? acc_shifter_out_l :
                     (reg_sel == REG_MASKGEN)   ? acc_mask_buf :
 `endif
                     32'hFFFFFFFF;
    wire [VMEM_ADDR_WIDTH-1:0] cpu_addr = vmem_wr_en ? cpu_wr_addr : cpu_rd_addr;
@ -212,7 +175,6 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
    wire scanline;                  // scanline start
    wire vblank;                    // vertical blank
    reg  vblank_buf;                // vertical blank in cpu clock domain
    reg  vblank_xfer;               // vertical blank clock domain crossing
    display_timings #(              // 640x480  800x600 1280x720 1920x1080
 `ifdef RES_1024_768
@ -238,18 +200,6 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
        .V_BP(35),
        .H_POL(0),
        .V_POL(1)
 `endif
 `ifdef RES_640_480
        .H_RES(640),               //     640      800     1280      1920
        .V_RES(480),                //     480      600      720      1080
        .H_FP(16),                 //      16       40      110        88
        .H_SYNC(96),                //      96      128       40        44
        .H_BP(48),                 //      48       88      220       148
        .V_FP(10),                   //      10        1        5         4
        .V_SYNC(2),                 //       2        4        5         5
        .V_BP(33),                  //      33       23       20        36
        .H_POL(0),                  //       0        1        1         1
        .V_POL(0)                   //       0        1        1         1
 `endif
    )
    display_timings_inst (
@ -265,8 +215,6 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
        .o_sy(sy)
    );
    wire pic_enable = (sy >= 0) && (sy < PIC_LINES);  // when to display pixels from VRAM
    wire [7:0] red;
    wire [7:0] green;
    wire [7:0] blue;
@ -285,7 +233,7 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
    always @(posedge pix_clk) frame_d <= frame;
-    always @(posedge cpu_clk) { vblank_buf, vblank_xfer } <= { vblank_xfer, vblank };
+    always @(posedge cpu_clk) vblank_buf <= vblank;
    always @(posedge cpu_clk)
    begin
@ -302,74 +250,6 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
        if(rd_en && reg_sel == REG_VMEM) cpu_rd_addr <= cpu_rd_addr + 1;           // auto-increment read addr on read
    end
 `ifdef ENABLE_FB_ACCEL
    //
    // shifter/masker registers
    //
    always @(posedge cpu_clk)
    begin
        if(wr_en && reg_sel == REG_SHIFTER)
            acc_shifter_in <= wr_data;
    end
    always @(posedge cpu_clk)
    begin
        if(wr_en && reg_sel == REG_SHIFTCOUNT)
        begin
            acc_shift_count <= { wr_data[2:0], 2'b0};
            acc_start_shift <= 1;
        end
        if(acc_start_shift)
            acc_start_shift <= 0;
    end
    always @(posedge cpu_clk)
    begin
        if (acc_start_shift)
            acc_shifter_out <= {acc_shifter_in, {VMEM_DATA_WIDTH{1'b0}}} >> acc_shift_count;
    end
    // mask register
    always @(posedge cpu_clk)
    begin
        if (wr_en && reg_sel == REG_MASKGEN)
            acc_mask_in <= wr_data;
    end
    // mask output is buffered to avoid timing problems
    always @(posedge cpu_clk)
    begin
        acc_mask_buf <= {
            {4{|{acc_mask_in[31:28]}}},
            {4{|{acc_mask_in[27:24]}}},
            {4{|{acc_mask_in[23:20]}}},
            {4{|{acc_mask_in[19:16]}}},
            {4{|{acc_mask_in[15:12]}}},
            {4{|{acc_mask_in[11:8]}}},
            {4{|{acc_mask_in[7:4]}}},
            {4{|{acc_mask_in[3:0]}}}
        };
    end
    always @(posedge cpu_clk)
    begin
        acc_shiftmask_buf = {
            {4{|{acc_shifter_out_h[31:28]}}},
            {4{|{acc_shifter_out_h[27:24]}}},
            {4{|{acc_shifter_out_h[23:20]}}},
            {4{|{acc_shifter_out_h[19:16]}}},
            {4{|{acc_shifter_out_h[15:12]}}},
            {4{|{acc_shifter_out_h[11:8]}}},
            {4{|{acc_shifter_out_h[7:4]}}},
            {4{|{acc_shifter_out_h[3:0]}}}
        };
    end
 `endif
    //
    // shifting pixels at pixel clock
    //
    always @(posedge pix_clk)
    begin
        if(scanline || shift_count == MAX_SHIFT_COUNT) // before start of a line
@ -406,7 +286,7 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
    // 12 bit RGB palette
    assign VGA_HS   = h_sync;
    assign VGA_VS   = v_sync;
-    assign VGA_R    = (pic_enable && de) ? color_data[11:8] : 4'b0;
+    assign VGA_R    = de ? color_data[11:8] : 4'b0;
-    assign VGA_G    = (pic_enable && de) ? color_data[7:4]  : 4'b0;
+    assign VGA_G    = de ? color_data[7:4]  : 4'b0;
-    assign VGA_B    = (pic_enable && de) ? color_data[3:0]  : 4'b0;
+    assign VGA_B    = de ? color_data[3:0]  : 4'b0;
 endmodule
--- a/tridoracpu/tridoracpu.xpr
+++ b/tridoracpu/tridoracpu.xpr
@ -1,10 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!-- Product Version: Vivado v2024.2.2 (64-bit)                              -->
+<!-- Product Version: Vivado v2020.1 (64-bit)              -->
 <!--                                                         -->
-<!-- Copyright 1986-2022 Xilinx, Inc. All Rights Reserved.                   -->
+<!-- Copyright 1986-2020 Xilinx, Inc. All Rights Reserved.   -->
 <!-- Copyright 2022-2025 Advanced Micro Devices, Inc. All Rights Reserved.   -->
-<Project Product="Vivado" Version="7" Minor="68" Path="C:/Users/sebastian/develop/Tridora/tridoracpu/tridoracpu.xpr">
+<Project Version="7" Minor="49" Path="./tridoracpu.xpr">
  <DefaultLaunch Dir="$PRUNDIR"/>
  <Configuration>
    <Option Name="Id" Val="ab60beb5e7ec4efc9a7b17699b9c3b13"/>
@ -13,48 +12,29 @@
    <Option Name="CompiledLibDirXSim" Val=""/>
    <Option Name="CompiledLibDirModelSim" Val="$PCACHEDIR/compile_simlib/modelsim"/>
    <Option Name="CompiledLibDirQuesta" Val="$PCACHEDIR/compile_simlib/questa"/>
    <Option Name="CompiledLibDirIES" Val="$PCACHEDIR/compile_simlib/ies"/>
    <Option Name="CompiledLibDirXcelium" Val="$PCACHEDIR/compile_simlib/xcelium"/>
    <Option Name="CompiledLibDirVCS" Val="$PCACHEDIR/compile_simlib/vcs"/>
    <Option Name="CompiledLibDirRiviera" Val="$PCACHEDIR/compile_simlib/riviera"/>
    <Option Name="CompiledLibDirActivehdl" Val="$PCACHEDIR/compile_simlib/activehdl"/>
    <Option Name="SimulatorInstallDirModelSim" Val=""/>
    <Option Name="SimulatorInstallDirQuesta" Val=""/>
    <Option Name="SimulatorInstallDirIES" Val=""/>
    <Option Name="SimulatorInstallDirXcelium" Val=""/>
    <Option Name="SimulatorInstallDirVCS" Val=""/>
    <Option Name="SimulatorInstallDirRiviera" Val=""/>
    <Option Name="SimulatorInstallDirActiveHdl" Val=""/>
-    <Option Name="SimulatorGccInstallDirModelSim" Val=""/>
+    <Option Name="BoardPart" Val="digilentinc.com:arty-a7-35:part0:1.0"/>
-    <Option Name="SimulatorGccInstallDirQuesta" Val=""/>
+    <Option Name="BoardPartRepoPaths" Val="$PPRDIR/../../../../AppData/Roaming/Xilinx/Vivado/2020.1/xhub/board_store/xilinx_board_store"/>
    <Option Name="SimulatorGccInstallDirXcelium" Val=""/>
    <Option Name="SimulatorGccInstallDirVCS" Val=""/>
    <Option Name="SimulatorGccInstallDirRiviera" Val=""/>
    <Option Name="SimulatorGccInstallDirActiveHdl" Val=""/>
    <Option Name="SimulatorVersionXsim" Val="2024.2"/>
    <Option Name="SimulatorVersionModelSim" Val="2024.1"/>
    <Option Name="SimulatorVersionQuesta" Val="2024.1"/>
    <Option Name="SimulatorVersionXcelium" Val="23.03.002"/>
    <Option Name="SimulatorVersionVCS" Val="U-2023.03-1"/>
    <Option Name="SimulatorVersionRiviera" Val="2024.04"/>
    <Option Name="SimulatorVersionActiveHdl" Val="15.0"/>
    <Option Name="SimulatorGccVersionXsim" Val="9.3.0"/>
    <Option Name="SimulatorGccVersionModelSim" Val="7.4.0"/>
    <Option Name="SimulatorGccVersionQuesta" Val="7.4.0"/>
    <Option Name="SimulatorGccVersionXcelium" Val="9.3.0"/>
    <Option Name="SimulatorGccVersionVCS" Val="9.2.0"/>
    <Option Name="SimulatorGccVersionRiviera" Val="9.3.0"/>
    <Option Name="SimulatorGccVersionActiveHdl" Val="9.3.0"/>
    <Option Name="BoardPart" Val=""/>
    <Option Name="SourceMgmtMode" Val="DisplayOnly"/>
    <Option Name="ActiveSimSet" Val="sim_sdspi"/>
    <Option Name="DefaultLib" Val="xil_defaultlib"/>
    <Option Name="ProjectType" Val="Default"/>
    <Option Name="IPOutputRepo" Val="$PCACHEDIR/ip"/>
-    <Option Name="IPDefaultOutputPath" Val="$PGENDIR/sources_1"/>
+    <Option Name="IPDefaultOutputPath" Val="$PSRCDIR/sources_1"/>
    <Option Name="IPCachePermission" Val="read"/>
    <Option Name="IPCachePermission" Val="write"/>
    <Option Name="EnableCoreContainer" Val="FALSE"/>
    <Option Name="EnableResourceEstimation" Val="FALSE"/>
    <Option Name="SimCompileState" Val="TRUE"/>
    <Option Name="CreateRefXciForCoreContainers" Val="FALSE"/>
    <Option Name="IPUserFilesDir" Val="$PIPUSERFILESDIR"/>
    <Option Name="IPStaticSourceDir" Val="$PIPUSERFILESDIR/ipstatic"/>
@ -67,13 +47,13 @@
    <Option Name="WTVcsLaunchSim" Val="0"/>
    <Option Name="WTRivieraLaunchSim" Val="0"/>
    <Option Name="WTActivehdlLaunchSim" Val="0"/>
-    <Option Name="WTXSimExportSim" Val="6"/>
+    <Option Name="WTXSimExportSim" Val="4"/>
-    <Option Name="WTModelSimExportSim" Val="6"/>
+    <Option Name="WTModelSimExportSim" Val="4"/>
-    <Option Name="WTQuestaExportSim" Val="6"/>
+    <Option Name="WTQuestaExportSim" Val="4"/>
    <Option Name="WTIesExportSim" Val="4"/>
-    <Option Name="WTVcsExportSim" Val="6"/>
+    <Option Name="WTVcsExportSim" Val="4"/>
-    <Option Name="WTRivieraExportSim" Val="6"/>
+    <Option Name="WTRivieraExportSim" Val="4"/>
-    <Option Name="WTActivehdlExportSim" Val="6"/>
+    <Option Name="WTActivehdlExportSim" Val="4"/>
    <Option Name="GenerateIPUpgradeLog" Val="TRUE"/>
    <Option Name="XSimRadix" Val="hex"/>
    <Option Name="XSimTimeUnit" Val="ns"/>
@ -85,11 +65,9 @@
    <Option Name="SimTypes" Val="tlm_dpi"/>
    <Option Name="MEMEnableMemoryMapGeneration" Val="TRUE"/>
    <Option Name="DcpsUptoDate" Val="TRUE"/>
    <Option Name="UseInlineHdlIP" Val="TRUE"/>
    <Option Name="LocalIPRepoLeafDirName" Val="ip_repo"/>
  </Configuration>
-  <FileSets Version="1" Minor="32">
+  <FileSets Version="1" Minor="31">
-    <FileSet Name="sources_1" Type="DesignSrcs" RelSrcDir="$PSRCDIR" RelGenDir="$PGENDIR/sources_1">
+    <FileSet Name="sources_1" Type="DesignSrcs" RelSrcDir="$PSRCDIR">
      <Filter Type="Srcs"/>
      <File Path="$PSRCDIR/cpuclk.v">
        <FileInfo>
@ -111,7 +89,7 @@
          <Attr Name="UsedIn" Val="implementation"/>
        </FileInfo>
      </File>
-      <File Path="$PSRCDIR/stack.v" Mode="RelativeOnly">
+      <File Path="$PSRCDIR/stack.v">
        <FileInfo>
          <Attr Name="UsedIn" Val="synthesis"/>
          <Attr Name="UsedIn" Val="implementation"/>
@ -142,7 +120,7 @@
        </FileInfo>
      </File>
      <File Path="$PSRCDIR/testbench.v"/>
-      <File Path="$PPRDIR/rom.mem" Mode="RelativeOnly">
+      <File Path="$PPRDIR/rom.mem">
        <FileInfo>
          <Attr Name="UsedIn" Val="synthesis"/>
          <Attr Name="UsedIn" Val="simulation"/>
@ -173,14 +151,14 @@
          <Attr Name="UsedIn" Val="simulation"/>
        </FileInfo>
      </File>
-      <File Path="$PSRCDIR/bram_tdp.v" Mode="RelativeOnly">
+      <File Path="$PSRCDIR/bram_tdp.v">
        <FileInfo>
          <Attr Name="UsedIn" Val="synthesis"/>
          <Attr Name="UsedIn" Val="implementation"/>
          <Attr Name="UsedIn" Val="simulation"/>
        </FileInfo>
      </File>
-      <File Path="$PSRCDIR/palette.v" Mode="RelativeOnly">
+      <File Path="$PSRCDIR/palette.v">
        <FileInfo>
          <Attr Name="UsedIn" Val="synthesis"/>
          <Attr Name="UsedIn" Val="implementation"/>
@ -205,19 +183,12 @@
          <Attr Name="UsedIn" Val="simulation"/>
        </FileInfo>
      </File>
      <File Path="$PSRCDIR/tdraudio.v">
        <FileInfo>
          <Attr Name="UsedIn" Val="synthesis"/>
          <Attr Name="UsedIn" Val="implementation"/>
          <Attr Name="UsedIn" Val="simulation"/>
        </FileInfo>
      </File>
      <Config>
        <Option Name="DesignMode" Val="RTL"/>
        <Option Name="TopModule" Val="top"/>
      </Config>
    </FileSet>
-    <FileSet Name="constrs_1" Type="Constrs" RelSrcDir="$PSRCDIR" RelGenDir="$PGENDIR/constrs_1">
+    <FileSet Name="constrs_1" Type="Constrs" RelSrcDir="$PSRCDIR">
      <Filter Type="Constrs"/>
      <File Path="$PSRCDIR/Arty-A7-35-Master.xdc">
        <FileInfo>
@ -230,7 +201,7 @@
        <Option Name="ConstrsType" Val="XDC"/>
      </Config>
    </FileSet>
-    <FileSet Name="sim_1" Type="SimulationSrcs" RelSrcDir="$PSRCDIR" RelGenDir="$PGENDIR/sim_1">
+    <FileSet Name="sim_1" Type="SimulationSrcs" RelSrcDir="$PSRCDIR">
      <Filter Type="Srcs"/>
      <File Path="$PSRCDIR/uart_tb.v"/>
      <File Path="$PPRDIR/testbench_behav1.wcfg">
@ -253,19 +224,28 @@
        <Option Name="SrcSet" Val="sources_1"/>
        <Option Name="XSimWcfgFile" Val="$PPRDIR/testbench_behav.wcfg"/>
        <Option Name="XSimWcfgFile" Val="$PPRDIR/testbench_behav1.wcfg"/>
        <Option Name="CosimPdi" Val=""/>
        <Option Name="CosimPlatform" Val=""/>
        <Option Name="CosimElf" Val=""/>
        <Option Name="NLNetlistMode" Val="funcsim"/>
      </Config>
    </FileSet>
-    <FileSet Name="utils_1" Type="Utils" RelSrcDir="$PSRCDIR/utils_1" RelGenDir="$PGENDIR/utils_1">
+    <FileSet Name="utils_1" Type="Utils" RelSrcDir="$PSRCDIR/utils_1">
      <Filter Type="Utils"/>
      <Config>
        <Option Name="TopAutoSet" Val="TRUE"/>
      </Config>
    </FileSet>
-    <FileSet Name="sim_fifo" Type="SimulationSrcs" RelSrcDir="$PSRCDIR/sim_fifo" RelGenDir="$PGENDIR/sim_fifo">
+    <FileSet Name="mig_dram_0" Type="BlockSrcs" RelSrcDir="$PSRCDIR/mig_dram_0">
      <File Path="$PSRCDIR/mig_dram_0/mig_dram_0.xci">
        <FileInfo>
          <Attr Name="UsedIn" Val="synthesis"/>
          <Attr Name="UsedIn" Val="implementation"/>
        </FileInfo>
      </File>
      <Config>
        <Option Name="TopModule" Val="mig_dram_0"/>
        <Option Name="UseBlackboxStub" Val="1"/>
      </Config>
    </FileSet>
    <FileSet Name="sim_fifo" Type="SimulationSrcs" RelSrcDir="$PSRCDIR/sim_fifo">
      <Filter Type="Srcs"/>
      <File Path="$PSRCDIR/fifo.v">
        <FileInfo>
@ -292,12 +272,9 @@
        <Option Name="PamSignalDriverFile" Val="xil_bypass_driver"/>
        <Option Name="PamPseudoTop" Val="pseudo_tb"/>
        <Option Name="SrcSet" Val="sources_1"/>
        <Option Name="CosimPdi" Val=""/>
        <Option Name="CosimPlatform" Val=""/>
        <Option Name="CosimElf" Val=""/>
      </Config>
    </FileSet>
-    <FileSet Name="sim_sdspi" Type="SimulationSrcs" RelSrcDir="$PSRCDIR/sim_sdspi" RelGenDir="$PGENDIR/sim_sdspi">
+    <FileSet Name="sim_sdspi" Type="SimulationSrcs" RelSrcDir="$PSRCDIR/sim_sdspi">
      <Filter Type="Srcs"/>
      <File Path="$PPRDIR/sdspi_testbench_behav.wcfg">
        <FileInfo>
@ -318,24 +295,9 @@
        <Option Name="PamPseudoTop" Val="pseudo_tb"/>
        <Option Name="SrcSet" Val="sources_1"/>
        <Option Name="XSimWcfgFile" Val="$PPRDIR/sdspi_testbench_behav.wcfg"/>
        <Option Name="CosimPdi" Val=""/>
        <Option Name="CosimPlatform" Val=""/>
        <Option Name="CosimElf" Val=""/>
        <Option Name="xsim.simulate.runtime" Val="10ms"/>
      </Config>
    </FileSet>
    <FileSet Name="mig_dram_0" Type="BlockSrcs" RelSrcDir="$PSRCDIR/mig_dram_0" RelGenDir="$PGENDIR/mig_dram_0">
      <File Path="$PSRCDIR/mig_dram_0/mig_dram_0.xci">
        <FileInfo>
          <Attr Name="UsedIn" Val="synthesis"/>
          <Attr Name="UsedIn" Val="implementation"/>
        </FileInfo>
      </File>
      <Config>
        <Option Name="TopModule" Val="mig_dram_0"/>
        <Option Name="UseBlackboxStub" Val="1"/>
      </Config>
    </FileSet>
  </FileSets>
  <Simulators>
    <Simulator Name="XSim">
@ -355,34 +317,56 @@
      <Option Name="Description" Val="Active-HDL Simulator"/>
    </Simulator>
  </Simulators>
-  <Runs Version="1" Minor="22">
+  <Runs Version="1" Minor="11">
-    <Run Id="synth_1" Type="Ft3:Synth" SrcSet="sources_1" Part="xc7a35ticsg324-1L" ConstrsSet="constrs_1" Description="Vivado Synthesis Defaults" AutoIncrementalCheckpoint="false" WriteIncrSynthDcp="false" State="current" Dir="$PRUNDIR/synth_1" IncludeInArchive="true" IsChild="false" AutoIncrementalDir="$PSRCDIR/utils_1/imports/synth_1" AutoRQSDir="$PSRCDIR/utils_1/imports/synth_1" ParallelReportGen="true">
+    <Run Id="synth_1" Type="Ft3:Synth" SrcSet="sources_1" Part="xc7a35ticsg324-1L" ConstrsSet="constrs_1" Description="Vivado Synthesis Defaults" AutoIncrementalCheckpoint="false" WriteIncrSynthDcp="false" State="current" Dir="$PRUNDIR/synth_1" IncludeInArchive="true">
      <Strategy Version="1" Minor="2">
-        <StratHandle Name="Vivado Synthesis Defaults" Flow="Vivado Synthesis 2024">
+        <StratHandle Name="Vivado Synthesis Defaults" Flow="Vivado Synthesis 2020"/>
          <Desc>Vivado Synthesis Defaults</Desc>
        </StratHandle>
        <Step Id="synth_design"/>
      </Strategy>
      <GeneratedRun Dir="$PRUNDIR" File="gen_run.xml"/>
-      <ReportStrategy Name="Vivado Synthesis Default Reports" Flow="Vivado Synthesis 2024"/>
+      <ReportStrategy Name="Vivado Synthesis Default Reports" Flow="Vivado Synthesis 2020"/>
      <Report Name="ROUTE_DESIGN.REPORT_METHODOLOGY" Enabled="1"/>
      <RQSFiles/>
    </Run>
-    <Run Id="mig_dram_0_synth_1" Type="Ft3:Synth" SrcSet="mig_dram_0" Part="xc7a35ticsg324-1L" ConstrsSet="mig_dram_0" Description="Vivado Synthesis Defaults" AutoIncrementalCheckpoint="false" WriteIncrSynthDcp="false" Dir="$PRUNDIR/mig_dram_0_synth_1" IncludeInArchive="true" IsChild="false" AutoIncrementalDir="$PSRCDIR/utils_1/imports/mig_dram_0_synth_1" AutoRQSDir="$PSRCDIR/utils_1/imports/mig_dram_0_synth_1" ParallelReportGen="true">
+    <Run Id="mig_dram_0_synth_1" Type="Ft3:Synth" SrcSet="mig_dram_0" Part="xc7a35ticsg324-1L" ConstrsSet="mig_dram_0" Description="Vivado Synthesis Defaults" AutoIncrementalCheckpoint="false" WriteIncrSynthDcp="false" Dir="$PRUNDIR/mig_dram_0_synth_1" IncludeInArchive="true">
      <Strategy Version="1" Minor="2">
-        <StratHandle Name="Vivado Synthesis Defaults" Flow="Vivado Synthesis 2024"/>
+        <StratHandle Name="Vivado Synthesis Defaults" Flow="Vivado Synthesis 2020"/>
        <Step Id="synth_design"/>
      </Strategy>
      <GeneratedRun Dir="$PRUNDIR" File="gen_run.xml"/>
-      <ReportStrategy Name="Vivado Synthesis Default Reports" Flow="Vivado Synthesis 2024"/>
+      <ReportStrategy Name="Vivado Synthesis Default Reports" Flow="Vivado Synthesis 2020"/>
      <Report Name="ROUTE_DESIGN.REPORT_METHODOLOGY" Enabled="1"/>
      <RQSFiles/>
    </Run>
-    <Run Id="impl_1" Type="Ft2:EntireDesign" Part="xc7a35ticsg324-1L" ConstrsSet="constrs_1" Description="Default settings for Implementation." AutoIncrementalCheckpoint="false" WriteIncrSynthDcp="false" State="current" Dir="$PRUNDIR/impl_1" SynthRun="synth_1" IncludeInArchive="true" IsChild="false" GenFullBitstream="true" AutoIncrementalDir="$PSRCDIR/utils_1/imports/impl_1" LaunchOptions="-jobs 6 " AutoRQSDir="$PSRCDIR/utils_1/imports/impl_1" ParallelReportGen="true">
+    <Run Id="impl_1" Type="Ft2:EntireDesign" Part="xc7a35ticsg324-1L" ConstrsSet="constrs_1" Description="Increase placer effort in the post-placement optimization phase, and disable timing relaxation in the router." AutoIncrementalCheckpoint="false" WriteIncrSynthDcp="false" State="current" Dir="$PRUNDIR/impl_1" SynthRun="synth_1" IncludeInArchive="true" GenFullBitstream="true">
      <Strategy Version="1" Minor="2">
-        <StratHandle Name="Vivado Implementation Defaults" Flow="Vivado Implementation 2024">
+        <StratHandle Name="Performance_RefinePlacement" Flow="Vivado Implementation 2020"/>
-          <Desc>Default settings for Implementation.</Desc>
+        <Step Id="init_design"/>
-        </StratHandle>
+        <Step Id="opt_design"/>
        <Step Id="power_opt_design"/>
        <Step Id="place_design">
          <Option Id="Directive">7</Option>
        </Step>
        <Step Id="post_place_power_opt_design"/>
        <Step Id="phys_opt_design">
          <Option Id="Directive">0</Option>
        </Step>
        <Step Id="route_design">
          <Option Id="Directive">0</Option>
        </Step>
        <Step Id="post_route_phys_opt_design"/>
        <Step Id="write_bitstream">
          <Option Id="BinFile">1</Option>
        </Step>
      </Strategy>
      <GeneratedRun Dir="$PRUNDIR" File="gen_run.xml"/>
      <ReportStrategy Name="Vivado Implementation Default Reports" Flow="Vivado Implementation 2020"/>
      <Report Name="ROUTE_DESIGN.REPORT_METHODOLOGY" Enabled="1"/>
      <RQSFiles/>
    </Run>
    <Run Id="mig_dram_0_impl_1" Type="Ft2:EntireDesign" Part="xc7a35ticsg324-1L" ConstrsSet="mig_dram_0" Description="Default settings for Implementation." AutoIncrementalCheckpoint="false" WriteIncrSynthDcp="false" SynthRun="mig_dram_0_synth_1" IncludeInArchive="false" GenFullBitstream="true">
      <Strategy Version="1" Minor="2">
        <StratHandle Name="Vivado Implementation Defaults" Flow="Vivado Implementation 2020"/>
        <Step Id="init_design"/>
        <Step Id="opt_design"/>
        <Step Id="power_opt_design"/>
@ -393,30 +377,14 @@
        <Step Id="post_route_phys_opt_design"/>
        <Step Id="write_bitstream"/>
      </Strategy>
-      <GeneratedRun Dir="$PRUNDIR" File="gen_run.xml"/>
+      <ReportStrategy Name="Vivado Implementation Default Reports" Flow="Vivado Implementation 2020"/>
      <ReportStrategy Name="Vivado Implementation Default Reports" Flow="Vivado Implementation 2024"/>
      <Report Name="ROUTE_DESIGN.REPORT_METHODOLOGY" Enabled="1"/>
      <RQSFiles/>
    </Run>
    <Run Id="mig_dram_0_impl_1" Type="Ft2:EntireDesign" Part="xc7a35ticsg324-1L" ConstrsSet="mig_dram_0" Description="Default settings for Implementation." AutoIncrementalCheckpoint="false" WriteIncrSynthDcp="false" SynthRun="mig_dram_0_synth_1" IncludeInArchive="false" IsChild="false" GenFullBitstream="true" AutoIncrementalDir="$PSRCDIR/utils_1/imports/mig_dram_0_impl_1" AutoRQSDir="$PSRCDIR/utils_1/imports/mig_dram_0_impl_1" ParallelReportGen="true">
      <Strategy Version="1" Minor="2">
        <StratHandle Name="Vivado Implementation Defaults" Flow="Vivado Implementation 2024"/>
        <Step Id="init_design"/>
        <Step Id="opt_design"/>
        <Step Id="power_opt_design"/>
        <Step Id="place_design"/>
        <Step Id="post_place_power_opt_design"/>
        <Step Id="phys_opt_design"/>
        <Step Id="route_design"/>
        <Step Id="post_route_phys_opt_design"/>
        <Step Id="write_bitstream"/>
      </Strategy>
      <ReportStrategy Name="Vivado Implementation Default Reports" Flow="Vivado Implementation 2024"/>
      <Report Name="ROUTE_DESIGN.REPORT_METHODOLOGY" Enabled="1"/>
      <RQSFiles/>
    </Run>
  </Runs>
-  <Board/>
+  <Board>
    <Jumpers/>
  </Board>
  <DashboardSummary Version="1" Minor="0">
    <Dashboards>
      <Dashboard Name="default_dashboard">
--- a/tridoraemu/ADDS-Envoy-620.pict
+++ b/tridoraemu/ADDS-Envoy-620.pict
--- a/tridoraemu/README.md
+++ b/tridoraemu/README.md
@ -5,7 +5,7 @@
 - written in Golang
 ## Getting started
-Download this zipfile: [tridoraemu.zip](https://git.insignificance.de/api/packages/slederer/generic/tridoraemu/0.0.5/tridoraemu.zip)
+Download this zipfile: [tridoraemu.zip](https://git.insignificance.de/api/packages/slederer/generic/tridoraemu/0.0.1/tridoraemu.zip)
 It contains the sources, the ROM image, an SD-card image and a precompiled windows binary.
@ -40,7 +40,7 @@ On the ROM monitor prompt, press *B* to boot from the SD-card image. This should
 In the shell, try the *L* command to list directories and the *V* command to change volumes. The *Examples* volume contains some example programs in source form.
-The programs *lines*, *conway* and *mandelbrot*, among others, show some (hopefully) interesting VGA graphics. The *pictviewer* program can show image files (*.pict files) which contain 640x400x4 bitmaps. A few sample image files are provided.
+The programs *lines*, *conway* and *mandelbrot*, among others, show some (hopefully) interesting VGA graphics. The *viewpict* program can show image files (*.pict files) which contain 640x400x4 bitmaps. A few sample image files are provided.
 To compile a program, set the file name (e.g. *lines.pas*) with the *W* command in the shell. Then, use *B* and *R* to build and run the program.
@ -50,9 +50,6 @@ The volume *Testvolume 1* (note the space) contains a precompiled game called *c
 You can run the program with the *O* command in the shell (just press Return for the program arguments), or you can set the workfile name with *W* and then use the *R* command.
 The volume *Rogue* contains a compiled version of ECL-Rogue, a Pascal variant of the
 classic Rogue game.
 The *K* command in the shell is used to reclaim the space occupied by deleted or overwritten files.
 A running program can be terminated by pressing Control-C, but only if the program is expecting keyboard input at that time.
--- a/tridoraemu/cpu.go
+++ b/tridoraemu/cpu.go
@ -125,7 +125,7 @@ func (c *CPU) step() error {
 	Y := c.estack[c.ESP]
-	insWord, err := c.mem.readIns(c.PC)
+	insWord, err := c.mem.read(c.PC)
 	if err != nil { return err }
 	if c.PC % 4 == 0 {
 		insWord = insWord >> 16
@ -249,7 +249,6 @@ func (c *CPU) step() error {
 		var name string
 		if (insWord & 1) == 1 {
 			name = "STORE.B"
 			operand &= ^1
 			ea = c.BP + word(operand)
 		} else {
 			name = "STORE"
--- a/tridoraemu/framebuffer.go
+++ b/tridoraemu/framebuffer.go
@ -10,16 +10,11 @@ import (
 const VmemWords = 32768
 const PaletteSlots = 16
 const FB_RA = 0
-const FB_WA = 4
+const FB_WA = 1
-const FB_IO = 8
+const FB_IO = 2
-const FB_PS = 12
+const FB_PS = 3
-const FB_PD = 16
+const FB_PD = 4
-const FB_CTL= 20
+const FB_CTL= 5
 const FB_SHIFTER = 24
 const FB_SHIFTCOUNT = 28
 const FB_SHIFTERM = 32
 const FB_SHIFTERSP = 36
 const FB_MASKGEN = 40
 const PixelMask = 0b11110000000000000000000000000000
 const PixelPerWord = 8
@ -37,10 +32,6 @@ type Framebuffer struct {
 	paletteSlot word
 	vmem [VmemWords]word
 	readCount int
        paletteChanged bool
 	shiftAssistData word
 	shiftAssistCount int
 	maskGenData word
 }
 func (f *Framebuffer) initialize() {
@ -61,11 +52,6 @@ func (f *Framebuffer) read(byteaddr word) (word, error) {
 	case FB_PS: result = f.paletteSlot
 	case FB_PD: result = f.readPalette()
 	case FB_CTL: result = f.readCtl()
 	case FB_SHIFTER: result = f.readShiftAssist()
 	case FB_SHIFTCOUNT: result = 0xFFFFFFF
 	case FB_SHIFTERM: result = f.readShifterM()
 	case FB_SHIFTERSP: result = f.readShifterSp()
 	case FB_MASKGEN: result = f.readMaskGen()
 	default:
 	}
 	return result, nil
@ -80,11 +66,6 @@ func (f *Framebuffer) write(value word, byteaddr word) (error) {
 	case FB_PS: f.paletteSlot = value
 	case FB_PD: f.writePalette(value)
 	case FB_CTL: f.writeCtl(value)
 	case FB_SHIFTER: f.writeShiftAssist(value)
 	case FB_SHIFTCOUNT: f.writeShiftCount(value)
 	case FB_SHIFTERM:
 	case FB_SHIFTERSP:
 	case FB_MASKGEN: f.writeMaskGen(value)
 	default:
 	}
@ -123,26 +104,6 @@ func (f *Framebuffer) readPalette() word {
 	return word(0)
 }
 func (f *Framebuffer) startFrame() {
 	// when the palette changes, we
 	// need to redraw every pixel
 	// to get the new colors
 	if f.paletteChanged {
 		oldRAddr := f.readAddr
 		oldWAddr := f.writeAddr
 		f.readAddr = 0
 		f.writeAddr = 0
 		for i := 0; i < VmemWords; i++ {
 			f.writeVmem(f.readVmem())
 		}
 		f.readAddr = oldRAddr
 		f.writeAddr = oldWAddr
 		f.paletteChanged = false
 	}
 }
 func (f *Framebuffer) writePalette(value word) {
 	// 4 bits per color channel
 	r := uint8((value & 0b111100000000) >> 8)
@ -155,7 +116,6 @@ func (f *Framebuffer) writePalette(value word) {
 	b = b << 4
 	f.palette[f.paletteSlot] = color.RGBA{r,g,b,0}
 	f.paletteChanged = true
 }
 func (f *Framebuffer) readCtl() word {
@ -170,47 +130,3 @@ func (f *Framebuffer) readCtl() word {
 func (f *Framebuffer) writeCtl(value word) {
 }
 func (f *Framebuffer) writeShiftAssist(value word) {
 	f.shiftAssistData = value
 	f.shiftAssistCount = 0
 }
 func (f *Framebuffer) readShiftAssist() word {
 	return f.shiftAssistData >> (f.shiftAssistCount * 4)
 }
 func (f *Framebuffer) writeShiftCount(value word) {
 	f.shiftAssistCount = int(value & 0x7)
 }
 func (f *Framebuffer) readShifterM() word {
 	return convertToMask(f.readShiftAssist())
 }
 func pixelToMask(pixels word, mask word) word {
 	if (pixels & mask) != 0 { return  mask } else { return 0 }
 }
 func convertToMask(pixels word) word {
 	return  pixelToMask(pixels, 0xF0000000) |
 		pixelToMask(pixels, 0x0F000000) |
 		pixelToMask(pixels, 0x00F00000) |
 		pixelToMask(pixels, 0x000F0000) |
 		pixelToMask(pixels, 0x0000F000) |
 		pixelToMask(pixels, 0x00000F00) |
 		pixelToMask(pixels, 0x000000F0) |
 		pixelToMask(pixels, 0x0000000F)
 }
 func (f *Framebuffer) readShifterSp() word {
 	return word(f.shiftAssistData << ((8-f.shiftAssistCount)*4))
 }
 func (f *Framebuffer) writeMaskGen(value word) {
 	f.maskGenData = value
 }
 func (f *Framebuffer) readMaskGen() word {
 	return convertToMask(f.maskGenData)
 }
--- a/tridoraemu/mem.go
+++ b/tridoraemu/mem.go
@ -17,12 +17,6 @@ const IOSlotSize = 128
 const IOSlotCount = 16
 const DRAMStart = 65536
 const CacheAddrShift = 8
 const CacheWriteThrough = true
 type Mem struct {
 	ram [] word
 	iohandler [IOSlotCount] IOHandler
@ -85,7 +79,7 @@ func (m *Mem) attachIO(h IOHandler, slot int) {
 	m.iohandler[slot] = h
 }
-func (m *Mem) readRaw(byteaddr word) (word, error) {
+func (m *Mem) read(byteaddr word) (word, error) {
 	if byteaddr >= IOStartAddr && byteaddr < RAMStartAddr {
 		ioslot := (byteaddr - IOStartAddr) / IOSlotSize
 		if m.iohandler[ioslot] != nil {
@ -102,14 +96,6 @@ func (m *Mem) readRaw(byteaddr word) (word, error) {
 	}
 }
 func (m *Mem) read(byteaddr word) (word, error) {
 	return m.readRaw(byteaddr);
 }
 func (m *Mem) readIns(byteaddr word) (word, error) {
 	return m.readRaw(byteaddr);
 }
 func (m *Mem) write(value word, byteaddr word) error {
 	if byteaddr < IOStartAddr {
 		return fmt.Errorf("Write to ROM area at %08X value %08X", byteaddr, value)
--- a/tridoraemu/tridoraemu.go
+++ b/tridoraemu/tridoraemu.go
@ -8,8 +8,7 @@ import (
 	"flag"
 	"time"
 	"github.com/hajimehoshi/ebiten/v2"
-	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
+	// "github.com/hajimehoshi/ebiten/v2/ebitenutil"
 	"github.com/hajimehoshi/ebiten/v2/inpututil"
 	// "image/color"
 )
@ -36,7 +35,6 @@ func idle(canGoIdle bool) {
 }
 type Game struct{
 		debug bool
 		x,y int
 		stepsPerFrame int
 		lastFrameDuration time.Duration
@ -45,7 +43,6 @@ type Game struct{
 func (g *Game) Update() error {
 	startTime := time.Now()
 	framebuffer.startFrame()
 	for i := 0; i < g.stepsPerFrame; i++ {
 		err := cpu.step()
 		if err != nil {
@ -60,23 +57,16 @@ func (g *Game) Update() error {
 	}
 	g.lastFrameDuration = time.Since(startTime)
 	if inpututil.IsKeyJustReleased(ebiten.KeyF12) {
 		g.debug = !g.debug
 	}
 	return nil
 }
 func (g *Game) Draw(screen *ebiten.Image) {
 	screen.DrawImage(framebuffer.framebuffer, nil)
 	if g.debug {
 		buf := fmt.Sprintf("PC: %08X FP: %08X RP: %08X ESP: %2X  %v",
 			cpu.PC, cpu.FP, cpu.RP, cpu.ESP, g.lastFrameDuration)
 		ebitenutil.DebugPrint(screen, buf)
 	}
 	/*
 	buf := fmt.Sprintf("PC: %08X FP: %08X RP: %08X ESP: %2X\n%v", cpu.PC, cpu.FP, cpu.RP, cpu.ESP, g.lastFrameDuration)
 	ebitenutil.DebugPrint(screen, buf)
 	screen.Set(g.x, g.y, color.RGBA{255,0,0,0})
 	screen.Set(g.x, g.y+1, color.RGBA{0,255,0,0})
 	screen.Set(g.x, g.y+2, color.RGBA{0,255,255,0})
--- a/utils/png2pict.py
+++ b/utils/png2pict.py
@ -1,118 +0,0 @@
 #!/usr/bin/python3
 import sys
 import png
 sprite_width = 32
 sprite_height = 32
 def process_pixdata(outfile, pixdata, frameindex = 0, pix_w=640, pix_h=400):
    pixmask = 15
    y = pix_h * frameindex
    max_y = y + pix_h - 1
    while y <= max_y:
        x = 0
        max_x = pix_w - 1
        pixline = pixdata[y]
        while x <= max_x:
            px1 = pixline[x+0] & pixmask
            px2 = pixline[x+1] & pixmask
            px3 = pixline[x+2] & pixmask
            px4 = pixline[x+3] & pixmask
            px5 = pixline[x+4] & pixmask
            px6 = pixline[x+5] & pixmask
            px7 = pixline[x+6] & pixmask
            px8 = pixline[x+7] & pixmask
            vmem_word = (px1 << 28) | (px2 << 24) | (px3 << 20) | (px4 << 16) | \
                        (px5 << 12) | (px6 << 8)  | (px7 << 4)  | px8
            outfile.write(vmem_word.to_bytes(4, 'big'))
            x += 8
        y += 1
 def write_palette_word(outfile, r, g, b):
    r4 = r >> 4
    g4 = g >> 4
    b4 = b >> 4
    c12 = r4 << 8 | g4 << 4 | b4
    outfile.write(c12.to_bytes(4, 'big'))
 def process_palette(outfile, palette):
    if len(palette[0]) == 4:
        for r,g,b,a in palette:
            write_palette_word(outfile, r, g, b)
    else:
        for r,g,b in palette:
            write_palette_word(outfile, r, g, b)
 def write_header(outfile):
    magic = b'PIct'
    mode = 1
    outfile.write(magic);
    outfile.write(mode.to_bytes(4, 'big'))
 def write_sprite_header(outfile):
    magic = b'SPRT'
    mode = 1
    outfile.write(magic);
    outfile.write(mode.to_bytes(4, 'big'))
 def write_pict_file(width, height, px, metadata, outfile):
    print("processing as PICT file...")
    if width != 640:
        print("width must be 640, aborting")
        sys.exit(1)
    pixdata = list(px)
    palette = metadata['palette']
    if len(palette) != 16:
        print("palette must have 16 colors, aborting")
        sys.exit(0)
    with open(outfile,'wb') as f:
        write_header(f)
        process_palette(f, palette)
        process_pixdata(f, pixdata)
 def write_sprite_file(width, height, px, metadata, outfile):
    print("processing as SPRT file with {} sprites...".format(height//sprite_height))
    if width != sprite_width:
        print("width must be {}, aborting".format(sprite_width))
        sys.exit(1)
    pixdata = list(px)
    palette = metadata['palette']
    if len(palette) != 16:
        print("palette must have 16 colors instead of {}, aborting".format(len(palette)))
        sys.exit(0)
    with open(outfile,'wb') as f:
        write_sprite_header(f)
        process_pixdata(f, pixdata, pix_w=sprite_width, pix_h=height)
 if __name__ == '__main__':
    if len(sys.argv) != 3:
        print("Usage: {} <infile> <outfile>".format(sys.argv[0]))
        sys.exit(1)
    infile = sys.argv[1]
    outfile = sys.argv[2]
    r = png.Reader(infile)
    p = r.read()
    width, height, px, metadata = p
    if width == 640:
        write_pict_file(width, height, px, metadata, outfile)
    elif width == sprite_width:
        write_sprite_file(width, height, px, metadata, outfile)
    else:
        print("Can't handle this file, need a width of\n640 or {} pixels with 16 color palette.".format(sprite_width))
--- a/utils/serload.py
+++ b/utils/serload.py
@ -1,398 +0,0 @@
 #!/usr/bin/python3
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4
 #
 # Copyright 2021 Sebastian Lederer
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import sys
 import os
 import serial
 import time
 import random
 import platform
 import argparse
 blocksize = 32
 BEL = 7
 ACK = 6
 NAK = 21
 ENQ = 5
 SOH = 1
 STX = 2
 EOT = 4
 wordmask = 0xFFFFFFFF
 pattern = 0xAFFECAFE
 def get_default_device():
    if platform.system() == 'Windows':
        return 'COM4:'
    else:
        return '/dev/ttyUSB1'
 def checksum(databytes):
    i = 0
    cksum = 0
    while i < len(databytes):
        word =  databytes[i]   << 24 | \
                databytes[i+1] << 16 | \
                databytes[i+2] << 8  | \
                databytes[i+3]
        # print("word:{0:08x}".format(word))
        i += 4
        cksum = (((cksum + word) ^ pattern) << 1) & wordmask
    return cksum
 def sendchar(char, ser):
    ser.write(char.to_bytes(1, 'big'))
 def sendcommand(ser, cmd=b'L', verbose=False):
    verbose = True
    ser.write(cmd)
    resp = ser.read_until()
    if verbose:
        print(cmd,"sent, response:", str(resp))
    return resp
 # send command and wait for echo
 def commandwait(ser, cmd):
    resp = sendcommand(ser, cmd, verbose=False)
    if len(resp) == 0:
        print("timeout sending '{}' command".format(cmd))
        return None
    if resp.startswith(b"> "):
        resp = resp[2:]
    if resp != bytearray(cmd + b"\r\n"):
        print("invalid response to '{}' command".format(cmd))
        return None
    return resp
 def send_size_header(ser, filesize):
    ser.write(b'\x05')  # ENQ
    resp = ser.read(1)
    if resp != b'\x15': # NAK
        # print("ENQ response:",str(resp))
        ser.write(b'\x01') # SOH
        databytes = filesize.to_bytes(4, 'big')
        chksum = ~filesize & 0xFFFFFFFF
        #print(str(databytes), len(databytes), type(filesize), filesize)
        #print(str(chksum.to_bytes(4,'big')), len(databytes))
        ser.write(databytes)
        ser.write(chksum.to_bytes(4,'big'))
        resp = ser.read(1)
        if len(resp) == 0:
            print("timeout waiting for ACK on size header")
            return False
        char = resp[0]
        # print("response to size header:", str(resp), repr(char))
        return char == ACK     # ACK
    else:
        print("Not using size header.")
        return True
 def serload_bin(datafile, ser):
    resp = sendcommand(ser)
    if len(resp) == 0:
        print("timeout sending 'L' command")
        return
    sentblocks = 0
    resend = 0
    data = []
    if datafile.endswith('.mem'):
        with open(datafile) as f:
            for l in f.readlines():
                b3 = l[0:8]
                b2 = l[8:16]
                b1 = l[16:24]
                b0 = l[24:32]
                data.extend([ int(b,2) for b in [b3,b2,b1,b0]])
    else:
        with open(datafile, 'rb') as f:
            data = f.read()
    filesize = len(data)
    if filesize % blocksize > 0:
        l = len(data)
        pad = blocksize - (l % blocksize)
        print("padding {} bytes with {} to {}".format(l, pad, l+pad))
        data += bytearray(pad)
    print("{} total blocks".format((len(data) + blocksize - 1) // blocksize))
    if not send_size_header(ser, filesize):
        print("Error sending size header.")
        return
    while len(data) > 0:
        block = data[0:32]
        databytes = bytearray(block)
        sendchar(STX, ser)
        #print("block:",databytes)
        chksum = checksum(databytes)
        #print("checksum: {0:08x}".format(chksum))
        #if random.randrange(2) == 0:
        #    databytes[random.randrange(len(databytes))] = 0
        ser.write(databytes)
        #print(chksum.to_bytes(4, 'big'))
        ser.write(chksum.to_bytes(4,'big'))
        resp = ser.read(1)
        if len(resp) == 0:
            print("timeout waiting for ACK")
            break
        char = resp[0]
        if char == ACK:
            #print("ACK received")
            sentblocks += 1
            data = data[32:] # ack received, send next block
        elif char == NAK:    # nak received, send same block
            # print("NAK received")
            resend += 1
            pass
        else:
            print("garbage received: ",char)
            print(ser.read(80))
            break            # anything else, give up
        print("{} blocks sent, {} retries".format(sentblocks, resend), end='\r')
    sendchar(EOT, ser)
    print()
 def word_from_bytes(b):
    w = b[0] << 24 | b[1] << 16  | b[2] << 8 | b[3]
    return w
 def read_word(ser):
    b = ser.read(4)
    if len(b) != 4:
        return None
    return word_from_bytes(b)
 def serdownload(fname, ser):
    resp = sendcommand(ser, b'D')
    if len(resp) == 0:
        print("timeout sending 'D' command")
        return
    sendchar(BEL, ser);
    resp = ser.read(1)
    if len(resp) == 0:
        print("Timeout receiving size header.")
        return
    if resp[0] != SOH:
        print("Error receiving size header.", resp[0])
        return
    size = read_word(ser)
    cksize = read_word(ser)
    if (~cksize & 0xFFFFFFFF) != size:
        print("Invalid size header received.")
        return
    sendchar(ACK, ser)
    print("File size: {} bytes".format(size))
    count = size
    with open(fname, "wb") as f:
        while count > 0:
            startbyte = ser.read(1)
            if len(startbyte) == 0:
                print("Timeout receiving STX.")
                return
            if startbyte[0] != STX:
                print("Error receiving STX.", resp[0])
                return
            block = ser.read(32)
            if len(block) != 32:
                print("Error receiving block")
                return
            cksum = read_word(ser)
            if cksum is None:
                print("Error receiving block checksum")
                return
            mysum = checksum(block)
            if cksum != mysum:
                print("Checksum error, retry block")
                sendchar(NAK, ser)
                continue
            print(".", end="", flush=True)
            count -= 32
            f.write(block)
            sendchar(ACK, ser)
        resp = ser.read(1)
        if len(resp) == 0:
            print("Timeout receiving EOT.")
        if resp[0] != EOT:
            print("Error receiving EOT.", resp[0])
        print("\nEnd of transmission, {} bytes received.".format(size))
        f.truncate(size)
        f.close()
 def mput(filenames, ser):
    for f in filenames:
        resp = set_filename(f, ser)
        if resp is None:
            return
        serload_bin(f, ser)
        resp = ser.read_until()
        time.sleep(2)
 def set_filename(f, ser):
    f_encoded = f.encode('utf8')
    print("Setting filename", f)
    resp = commandwait(ser, b'S')
    if resp is None:
        return None
    resp = sendcommand(ser, f_encoded + b'\r')
    if not f_encoded in resp:
        print("unrecognized response to filename, aborting")
        return None
    return resp
 def getnamedfile(filename, ser):
    resp = set_filename(filename, ser)
    if resp is None:
        return None
    serdownload(filename, ser)
 def putnamedfile(filename, ser):
    resp = set_filename(filename, ser)
    if resp is None:
        return None
    serload_bin(filename, ser)
    print("Remote status:")
    showdata(ser)
 def showdata(ser):
    promptseen = False
    while not promptseen:
        c = ser.read(1)
        if c == b'>':
            promptseen = True
        else:
            print(c.decode('utf8'), end='')
    rest = ser.read(1) # read trailing space of prompt
 def localdir():
    result = os.walk(".")
    for dirpath, dirnames, filenames in os.walk("."):
        for f in filenames:
            print(f)
        break
 def interactive(ser):
    done = False
    while not done:
        args = input("> ").strip().split()
        if len(args) > 0:
            cmd = args[0]
            args.pop(0)
            if cmd == 'dir':
                if commandwait(ser, b'Y') is None:
                    return
                showdata(ser)
            elif cmd == 'get':
                if len(args) > 1:
                    print("exactly one argument required (filename)")
                else:
                    getnamedfile(args[0], ser)
            elif cmd == 'put':
                if len(args) > 1:
                    print("exactly one argument required (filename)")
                else:
                    putnamedfile(args[0], ser)
            elif cmd == 'ldir':
                if len(args) > 0:
                    print("superfluous argument")
                else:
                    localdir()
            elif cmd == 'exit' or cmd == 'x':
                done = True
            else:
                print("Unknown command. Valid commands are: dir get ldir put exit")
 if __name__ == "__main__":
    argparser = argparse.ArgumentParser(
        description='transfer files from/to the Tridora-CPU')
    argparser.add_argument('-d', '--device', help='serial device', default=get_default_device())
    argparser.add_argument('command', choices=['get', 'put', 'mput', 'interactive'])
    argparser.add_argument('filename', nargs='*')
    args = argparser.parse_args()
    cmd = args.command
    serial_port = args.device
    filenames = args.filename
    ser = serial.Serial(serial_port,115200, timeout=3)
    if cmd == 'get':
        serdownload(filenames[0], ser)
    elif cmd == 'put':
        serload_bin(filenames[0], ser)
    elif cmd == 'mput':
        mput(filenames, ser)
    elif cmd == 'interactive':
        interactive(ser)
    else:
        print("should not get here")
    #if cmd is not None:
    #    ser.close()
--- a/utils/tdrimg.py
+++ b/utils/tdrimg.py
@ -1,6 +1,6 @@
 #!/usr/bin/python3
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4
-# Copyright 2021-2025 Sebastian Lederer. See the file LICENSE.md for details
+# Copyright 2021-2024 Sebastian Lederer. See the file LICENSE.md for details
 import struct
 import sys
@ -239,7 +239,7 @@ def listvolumes(img):
    return firstvolume
-def listdir(img, part, verbose=False, deleted=False):
+def listdir(img, part, verbose=False):
    print("Directory of {}:".format(part.name))
    slotno = 0
    done = False
@ -247,8 +247,6 @@ def listdir(img, part, verbose=False, deleted=False):
        slot = getdirslot(img, part, slotno)
        if (slot.flags & SlotFirst):
            print(slot.name, slot.sizeBytes, slotno)
        elif deleted and (slot.flags & SlotDeleted):
            print(slot.name, slot.sizeBytes, slotno, slot.generation)
        else:
            if verbose:
                print(flags2str(slot.flags))
@ -274,21 +272,6 @@ def findfile(img, part, name):
    return None
 def finddeleted(img, part, name, gen):
    slotno = 0
    done = False
    while not done:
        slot = getdirslot(img, part, slotno)
        if slot.flags & SlotDeleted:
            if slot.name == name and slot.generation == gen:
                return slotno
        slotno += 1
        if (slot.flags & SlotEndScan) or (slotno >= part.dirSize):
            done = True
    return None
 def readfile(img, part, slotno):
    pos = part.startBlock * 512 + slotno * part.extentSize
    dirslot = getdirslot(img, part, slotno)
@ -334,24 +317,6 @@ def readfromimg(img, pathname,outfilepath):
        f.write(data)
 def recoverfromimg(img, pathname, gen, outfilepath):
    vol, filename = parsepath(img, pathname)
    if vol is None:
        return
    listdir(img, vol, deleted=True)
    slotno = finddeleted(img, vol, filename, gen)
    if slotno is None:
        print("File", filename,"not found with generation no", gen)
        return
    data = readfile(img, vol, slotno)
    with open(outfilepath, "wb") as f:
        f.write(data)
 def writetoimg(img, pathname, infilepath):
    vol, filename = parsepath(img, pathname)
    if vol is None:
@ -372,32 +337,8 @@ def writetoimg(img, pathname, infilepath):
    putfile(infilepath, filename, img, vol, vol.startBlock, slotno)
-def initfs(f, partno):
+def create_image_with_stuff():
-    part = getpartslot(f, partno)
+    imgfile = "sdcard.img"
    partstart = part.startBlock
    dir_slots = part.dirSize
    extent_size = part.extentSize
    slots_per_extent = extent_size // 64
    reserved_slots = dir_slots // slots_per_extent
    print()
    print("Partition {} at {}".format(part.name, part.startBlock))
    print("creating",reserved_slots, "reserved directory slots")
    for a in range(0,reserved_slots):
        d = createdirslot("DIR", SlotReserved, 0, 0, 0, 0, 0)
        putdirslot(f, partstart, a, d)
    print("creating", dir_slots - reserved_slots, "free slots")
    for a in range(reserved_slots,  dir_slots):
        d = createdirslot("", SlotFree, 0, 0, 0, 0, 0)
        putdirslot(f, partstart, a, d)
    return (part, partstart, reserved_slots)
 def create_image_with_stuff(imgfile):
    bootimage = "../lib/coreloader.prog"
    dir_slots = 256
    extent_size = 8192
@ -406,27 +347,22 @@ def create_image_with_stuff(imgfile):
    f = open(imgfile,"w+b")
-    b = createpart("PHYS", PartPhysical, 0, 16384, 4096, 0, 0)
+    b = createpart("PHYS", PartPhysical, 0, 12288, 4096, 0, 0)
    #print(b)
    f.write(b)
    with open(bootimage, "rb") as bf:
        bootdata = bf.read()
    bootBlocks = len(bootdata) // 512 + 1
    b = createpart("BOOT", PartBoot, 16, 112, 0, 0, bootBlocks)
    f.write(b)
    b = createpart("Testvolume 1", PartEnabled, 128, 3968, 8192, 248)
    f.write(b)
    b = createpart("SYSTEM", PartEnabled, 4096, 4096, 8192, 256)
    f.write(b)
-    b = createpart("Examples", PartEnabled, 8192, 4096, 8192, 256)
+    b = createpart("Examples", PartEnabled + PartLast, 8192, 4096, 8192, 256)
    f.write(b)
    b = createpart("Rogue", PartEnabled + PartLast, 12288, 4096, 8192, 256)
    f.write(b)
    part = getpartslot(f, 2)
@ -535,11 +471,6 @@ def create_image_with_stuff(imgfile):
    slotnr = putfile("../progs/editor.pas", None , f, part, partstart, slotnr)
    slotnr = putfile("../progs/editor.prog", None , f, part, partstart, slotnr)
    slotnr = putfile("../progs/xfer.prog", None , f, part, partstart, slotnr)
    slotnr = putfile("../progs/recover.prog", None , f, part, partstart, slotnr)
    slotnr = putfile("../progs/changemem.prog", None , f, part, partstart, slotnr)
    slotnr = putfile("../lib/pcmaudio.s", None , f, part, partstart, slotnr)
    slotnr = putfile("../lib/pcmaudio.inc", None , f, part, partstart, slotnr)
    listdir(f, part)
@ -575,10 +506,10 @@ def create_image_with_stuff(imgfile):
    # slotnr = putfile("../tests/timetest.prog", None , f, part, partstart, slotnr)
    slotnr = putfile("../tests/readtest.pas", None , f, part, partstart, slotnr)
-    #slotnr = putfile("../tests/readtest.prog", None , f, part, partstart, slotnr)
+    slotnr = putfile("../tests/readtest.prog", None , f, part, partstart, slotnr)
    slotnr = putfile("../tests/readchartest.pas", None , f, part, partstart, slotnr)
-    #slotnr = putfile("../tests/readchartest.prog", None , f, part, partstart, slotnr)
+    slotnr = putfile("../tests/readchartest.prog", None , f, part, partstart, slotnr)
    # slotnr = putfile("cchangetest.pas", None , f, part, partstart, slotnr)
    # slotnr = putfile("cchangetest.prog", None , f, part, partstart, slotnr)
@ -588,13 +519,16 @@ def create_image_with_stuff(imgfile):
    slotnr = putfile("../tests/test133.pas", None , f, part, partstart, slotnr)
    # slotnr = putfile("../tests/test133.prog", None , f, part, partstart, slotnr)
-    # slotnr = putfile("../tests/test159.pas", None , f, part, partstart, slotnr)
+    slotnr = putfile("../tests/test159.pas", None , f, part, partstart, slotnr)
    # slotnr = putfile("../tests/test159.prog", None , f, part, partstart, slotnr)
    slotnr = putfile("../tests/umlaut.pas", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/rtpair.pas", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/5cubes.pas", None , f, part, partstart, slotnr)
    # slotnr = putfile("../examples/5cubes.prog", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/3dcube.pas", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/conway.pas", None , f, part, partstart, slotnr)
@ -603,33 +537,11 @@ def create_image_with_stuff(imgfile):
    slotnr = putfile("../examples/lines.pas", None , f, part, partstart, slotnr)
-    slotnr = putfile("../examples/pcmtest2.pas", None , f, part, partstart, slotnr)
+    slotnr = putfile("../examples/viewpict.pas", None , f, part, partstart, slotnr)
-
+    # slotnr = putfile("viewpict.prog", None , f, part, partstart, slotnr)
-    slotnr = putfile("../examples/pictviewer.pas", None , f, part, partstart, slotnr)
+    slotnr = putfile("../examples/ara.pict", "ara.pict" , f, part, partstart, slotnr)
-    slotnr = putfile("../examples/Toco_Toucan.pict", None , f, part, partstart, slotnr)
+    slotnr = putfile("../examples/shinkansen.pict", "shinkansen.pict" , f, part, partstart, slotnr)
-    slotnr = putfile("../examples/shinkansen.pict", None , f, part, partstart, slotnr)
+    slotnr = putfile("../examples/snow_leopard.pict", "snow_leopard.pict" , f, part, partstart, slotnr)
    slotnr = putfile("../examples/snow_leopard.pict", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/ADDS-Envoy-620.pict", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/benchmarks.pas", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/animate.pas", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/graphbench.pas", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/sprites.inc", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/sprites.s", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/background.pict", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/walking.sprt", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/rocket.sprt", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/sprite-testcard.sprt", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/tiles.inc", None , f, part, partstart, slotnr)
    slotnr = putfile("../examples/tiles.s", None , f, part, partstart, slotnr)
    listdir(f, part)
    part, partstart, slotnr = initfs(f, 5)
    slotnr = putfile("../rogue/rogue.init", None, f, part, partstart, slotnr)
    slotnr = putfile("../rogue/rogue.message", None, f, part, partstart, slotnr)
    slotnr = putfile("../rogue/rogue.prog", None, f, part, partstart, slotnr)
    listdir(f, part)
@ -643,14 +555,11 @@ if __name__ == "__main__":
        if sys.argv[1] == "get":
            f = open(sys.argv[2], "rb")
            readfromimg(f, sys.argv[3], sys.argv[4])
        elif sys.argv[1] == "recover":
            f = open(sys.argv[2], "rb")
            recoverfromimg(f, sys.argv[3], int(sys.argv[4]), sys.argv[5])
        elif sys.argv[1] == "put":
            imgfile = open(sys.argv[2], "r+b")
            infilepath = sys.argv[3]
            destfilename = sys.argv[4]
            writetoimg(imgfile, destfilename, infilepath)
        elif sys.argv[1] == "createimg":
-            create_image_with_stuff(sys.argv[2])
+            create_image_with_stuff()
        sys.exit(0)
--- a/utils/wav2tdrau.py
+++ b/utils/wav2tdrau.py
@ -1,29 +0,0 @@
 import sys
 import random, struct
 import wave
 freq = 16000
 BIAS = 32768
 def convert(srcpath, destpath):
 	outdata = bytearray()
 	with wave.open(srcpath, mode="rb") as f:
 		params = f.getparams()
 		print(params.nchannels, params.sampwidth, params.framerate)
 		frames = f.readframes(2*1024*1024)
 		for i in range(0, len(frames), 2):
 			v = int.from_bytes(frames[i:i+2], "little", signed=True)
 			v += BIAS
 			hi = (v & 0xFF00) >> 8
 			lo = (v & 0x00FF)
 			outdata.append(hi)
 			outdata.append(lo)
 	with open(destpath, mode="wb") as f:
 		f.write(outdata)
 if __name__ == "__main__":
 	sourcefilename = sys.argv[1]
 	destfilename = sys.argv[2]
 	convert(sourcefilename, destfilename)
		`@ -1 +0,0 @@`
			`Subproject commit 73936b4167bad01642675252e53a096d80fa6b35`